diff --git a/source/extern/lauxlib.h b/source/extern/lauxlib.h
index 0bac246..9857d3a 100644
--- a/source/extern/lauxlib.h
+++ b/source/extern/lauxlib.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.h,v 1.128 2014/10/29 16:11:17 roberto Exp $
+** $Id: lauxlib.h,v 1.131.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -16,10 +16,18 @@
 
 
 
-/* extra error code for 'luaL_load' */
+/* extra error code for 'luaL_loadfilex' */
 #define LUA_ERRFILE     (LUA_ERRERR+1)
 
 
+/* key, in the registry, for table of loaded modules */
+#define LUA_LOADED_TABLE	"_LOADED"
+
+
+/* key, in the registry, for table of preloaded loaders */
+#define LUA_PRELOAD_TABLE	"_PRELOAD"
+
+
 typedef struct luaL_Reg {
   const char *name;
   lua_CFunction func;
@@ -65,7 +73,7 @@ LUALIB_API int (luaL_checkoption) (lua_State *L, int arg, const char *def,
 LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname);
 LUALIB_API int (luaL_execresult) (lua_State *L, int stat);
 
-/* pre-defined references */
+/* predefined references */
 #define LUA_NOREF       (-2)
 #define LUA_REFNIL      (-1)
 
diff --git a/source/extern/lua.h b/source/extern/lua.h
index 1c2b95a..9394c5e 100644
--- a/source/extern/lua.h
+++ b/source/extern/lua.h
@@ -1,5 +1,4 @@
 /*
-** $Id: lua.h,v 1.328 2015/06/03 13:03:38 roberto Exp $
 ** Lua - A Scripting Language
 ** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
 ** See Copyright Notice at the end of this file
@@ -19,11 +18,11 @@
 #define LUA_VERSION_MAJOR	"5"
 #define LUA_VERSION_MINOR	"3"
 #define LUA_VERSION_NUM		503
-#define LUA_VERSION_RELEASE	"1"
+#define LUA_VERSION_RELEASE	"6"
 
 #define LUA_VERSION	"Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR
 #define LUA_RELEASE	LUA_VERSION "." LUA_VERSION_RELEASE
-#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2015 Lua.org, PUC-Rio"
+#define LUA_COPYRIGHT	LUA_RELEASE "  Copyright (C) 1994-2020 Lua.org, PUC-Rio"
 #define LUA_AUTHORS	"R. Ierusalimschy, L. H. de Figueiredo, W. Celes"
 
 
@@ -361,7 +360,7 @@ LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 #define lua_pushliteral(L, s)	lua_pushstring(L, "" s)
 
 #define lua_pushglobaltable(L)  \
-	lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS)
+	((void)lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS))
 
 #define lua_tostring(L,i)	lua_tolstring(L, (i), NULL)
 
@@ -460,7 +459,7 @@ struct lua_Debug {
 
 
 /******************************************************************************
-* Copyright (C) 1994-2015 Lua.org, PUC-Rio.
+* Copyright (C) 1994-2020 Lua.org, PUC-Rio.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
diff --git a/source/extern/lua/lapi.c b/source/extern/lua/lapi.c
index fea9eb2..711895b 100644
--- a/source/extern/lua/lapi.c
+++ b/source/extern/lua/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.249 2015/04/06 12:23:48 roberto Exp $
+** $Id: lapi.c,v 2.259.1.2 2017/12/06 18:35:12 roberto Exp $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -121,11 +121,11 @@ LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
   lua_lock(to);
   api_checknelems(from, n);
   api_check(from, G(from) == G(to), "moving among independent states");
-  api_check(from, to->ci->top - to->top >= n, "not enough elements to move");
+  api_check(from, to->ci->top - to->top >= n, "stack overflow");
   from->top -= n;
   for (i = 0; i < n; i++) {
     setobj2s(to, to->top, from->top + i);
-    api_incr_top(to);
+    to->top++;  /* stack already checked by previous 'api_check' */
   }
   lua_unlock(to);
 }
@@ -378,9 +378,9 @@ LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) {
       return NULL;
     }
     lua_lock(L);  /* 'luaO_tostring' may create a new string */
+    luaO_tostring(L, o);
     luaC_checkGC(L);
     o = index2addr(L, idx);  /* previous call may reallocate the stack */
-    luaO_tostring(L, o);
     lua_unlock(L);
   }
   if (len != NULL)
@@ -471,13 +471,18 @@ LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) {
 }
 
 
+/*
+** Pushes on the stack a string with given length. Avoid using 's' when
+** 'len' == 0 (as 's' can be NULL in that case), due to later use of
+** 'memcmp' and 'memcpy'.
+*/
 LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) {
   TString *ts;
   lua_lock(L);
-  luaC_checkGC(L);
-  ts = luaS_newlstr(L, s, len);
+  ts = (len == 0) ? luaS_new(L, "") : luaS_newlstr(L, s, len);
   setsvalue2s(L, L->top, ts);
   api_incr_top(L);
+  luaC_checkGC(L);
   lua_unlock(L);
   return getstr(ts);
 }
@@ -489,12 +494,12 @@ LUA_API const char *lua_pushstring (lua_State *L, const char *s) {
     setnilvalue(L->top);
   else {
     TString *ts;
-    luaC_checkGC(L);
     ts = luaS_new(L, s);
     setsvalue2s(L, L->top, ts);
     s = getstr(ts);  /* internal copy's address */
   }
   api_incr_top(L);
+  luaC_checkGC(L);
   lua_unlock(L);
   return s;
 }
@@ -504,8 +509,8 @@ LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt,
                                       va_list argp) {
   const char *ret;
   lua_lock(L);
-  luaC_checkGC(L);
   ret = luaO_pushvfstring(L, fmt, argp);
+  luaC_checkGC(L);
   lua_unlock(L);
   return ret;
 }
@@ -515,10 +520,10 @@ LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) {
   const char *ret;
   va_list argp;
   lua_lock(L);
-  luaC_checkGC(L);
   va_start(argp, fmt);
   ret = luaO_pushvfstring(L, fmt, argp);
   va_end(argp);
+  luaC_checkGC(L);
   lua_unlock(L);
   return ret;
 }
@@ -528,12 +533,12 @@ LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
   lua_lock(L);
   if (n == 0) {
     setfvalue(L->top, fn);
+    api_incr_top(L);
   }
   else {
     CClosure *cl;
     api_checknelems(L, n);
     api_check(L, n <= MAXUPVAL, "upvalue index too large");
-    luaC_checkGC(L);
     cl = luaF_newCclosure(L, n);
     cl->f = fn;
     L->top -= n;
@@ -542,8 +547,9 @@ LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) {
       /* does not need barrier because closure is white */
     }
     setclCvalue(L, L->top, cl);
+    api_incr_top(L);
+    luaC_checkGC(L);
   }
-  api_incr_top(L);
   lua_unlock(L);
 }
 
@@ -579,19 +585,30 @@ LUA_API int lua_pushthread (lua_State *L) {
 */
 
 
-LUA_API int lua_getglobal (lua_State *L, const char *name) {
-  Table *reg = hvalue(&G(L)->l_registry);
-  const TValue *gt;  /* global table */
-  lua_lock(L);
-  gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
-  setsvalue2s(L, L->top, luaS_new(L, name));
-  api_incr_top(L);
-  luaV_gettable(L, gt, L->top - 1, L->top - 1);
+static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
+  const TValue *slot;
+  TString *str = luaS_new(L, k);
+  if (luaV_fastget(L, t, str, slot, luaH_getstr)) {
+    setobj2s(L, L->top, slot);
+    api_incr_top(L);
+  }
+  else {
+    setsvalue2s(L, L->top, str);
+    api_incr_top(L);
+    luaV_finishget(L, t, L->top - 1, L->top - 1, slot);
+  }
   lua_unlock(L);
   return ttnov(L->top - 1);
 }
 
 
+LUA_API int lua_getglobal (lua_State *L, const char *name) {
+  Table *reg = hvalue(&G(L)->l_registry);
+  lua_lock(L);
+  return auxgetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
+}
+
+
 LUA_API int lua_gettable (lua_State *L, int idx) {
   StkId t;
   lua_lock(L);
@@ -603,24 +620,25 @@ LUA_API int lua_gettable (lua_State *L, int idx) {
 
 
 LUA_API int lua_getfield (lua_State *L, int idx, const char *k) {
-  StkId t;
   lua_lock(L);
-  t = index2addr(L, idx);
-  setsvalue2s(L, L->top, luaS_new(L, k));
-  api_incr_top(L);
-  luaV_gettable(L, t, L->top - 1, L->top - 1);
-  lua_unlock(L);
-  return ttnov(L->top - 1);
+  return auxgetstr(L, index2addr(L, idx), k);
 }
 
 
 LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) {
   StkId t;
+  const TValue *slot;
   lua_lock(L);
   t = index2addr(L, idx);
-  setivalue(L->top, n);
-  api_incr_top(L);
-  luaV_gettable(L, t, L->top - 1, L->top - 1);
+  if (luaV_fastget(L, t, n, slot, luaH_getint)) {
+    setobj2s(L, L->top, slot);
+    api_incr_top(L);
+  }
+  else {
+    setivalue(L->top, n);
+    api_incr_top(L);
+    luaV_finishget(L, t, L->top - 1, L->top - 1, slot);
+  }
   lua_unlock(L);
   return ttnov(L->top - 1);
 }
@@ -666,12 +684,12 @@ LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) {
 LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
   Table *t;
   lua_lock(L);
-  luaC_checkGC(L);
   t = luaH_new(L);
   sethvalue(L, L->top, t);
   api_incr_top(L);
   if (narray > 0 || nrec > 0)
     luaH_resize(L, t, narray, nrec);
+  luaC_checkGC(L);
   lua_unlock(L);
 }
 
@@ -719,18 +737,29 @@ LUA_API int lua_getuservalue (lua_State *L, int idx) {
 ** set functions (stack -> Lua)
 */
 
+/*
+** t[k] = value at the top of the stack (where 'k' is a string)
+*/
+static void auxsetstr (lua_State *L, const TValue *t, const char *k) {
+  const TValue *slot;
+  TString *str = luaS_new(L, k);
+  api_checknelems(L, 1);
+  if (luaV_fastset(L, t, str, slot, luaH_getstr, L->top - 1))
+    L->top--;  /* pop value */
+  else {
+    setsvalue2s(L, L->top, str);  /* push 'str' (to make it a TValue) */
+    api_incr_top(L);
+    luaV_finishset(L, t, L->top - 1, L->top - 2, slot);
+    L->top -= 2;  /* pop value and key */
+  }
+  lua_unlock(L);  /* lock done by caller */
+}
+
 
 LUA_API void lua_setglobal (lua_State *L, const char *name) {
   Table *reg = hvalue(&G(L)->l_registry);
-  const TValue *gt;  /* global table */
-  lua_lock(L);
-  api_checknelems(L, 1);
-  gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
-  setsvalue2s(L, L->top, luaS_new(L, name));
-  api_incr_top(L);
-  luaV_settable(L, gt, L->top - 1, L->top - 2);
-  L->top -= 2;  /* pop value and key */
-  lua_unlock(L);
+  lua_lock(L);  /* unlock done in 'auxsetstr' */
+  auxsetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
 }
 
 
@@ -746,42 +775,40 @@ LUA_API void lua_settable (lua_State *L, int idx) {
 
 
 LUA_API void lua_setfield (lua_State *L, int idx, const char *k) {
-  StkId t;
-  lua_lock(L);
-  api_checknelems(L, 1);
-  t = index2addr(L, idx);
-  setsvalue2s(L, L->top, luaS_new(L, k));
-  api_incr_top(L);
-  luaV_settable(L, t, L->top - 1, L->top - 2);
-  L->top -= 2;  /* pop value and key */
-  lua_unlock(L);
+  lua_lock(L);  /* unlock done in 'auxsetstr' */
+  auxsetstr(L, index2addr(L, idx), k);
 }
 
 
 LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) {
   StkId t;
+  const TValue *slot;
   lua_lock(L);
   api_checknelems(L, 1);
   t = index2addr(L, idx);
-  setivalue(L->top, n);
-  api_incr_top(L);
-  luaV_settable(L, t, L->top - 1, L->top - 2);
-  L->top -= 2;  /* pop value and key */
+  if (luaV_fastset(L, t, n, slot, luaH_getint, L->top - 1))
+    L->top--;  /* pop value */
+  else {
+    setivalue(L->top, n);
+    api_incr_top(L);
+    luaV_finishset(L, t, L->top - 1, L->top - 2, slot);
+    L->top -= 2;  /* pop value and key */
+  }
   lua_unlock(L);
 }
 
 
 LUA_API void lua_rawset (lua_State *L, int idx) {
   StkId o;
-  Table *t;
+  TValue *slot;
   lua_lock(L);
   api_checknelems(L, 2);
   o = index2addr(L, idx);
   api_check(L, ttistable(o), "table expected");
-  t = hvalue(o);
-  setobj2t(L, luaH_set(L, t, L->top-2), L->top-1);
-  invalidateTMcache(t);
-  luaC_barrierback(L, t, L->top-1);
+  slot = luaH_set(L, hvalue(o), L->top - 2);
+  setobj2t(L, slot, L->top - 1);
+  invalidateTMcache(hvalue(o));
+  luaC_barrierback(L, hvalue(o), L->top-1);
   L->top -= 2;
   lua_unlock(L);
 }
@@ -789,14 +816,12 @@ LUA_API void lua_rawset (lua_State *L, int idx) {
 
 LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
   StkId o;
-  Table *t;
   lua_lock(L);
   api_checknelems(L, 1);
   o = index2addr(L, idx);
   api_check(L, ttistable(o), "table expected");
-  t = hvalue(o);
-  luaH_setint(L, t, n, L->top - 1);
-  luaC_barrierback(L, t, L->top-1);
+  luaH_setint(L, hvalue(o), n, L->top - 1);
+  luaC_barrierback(L, hvalue(o), L->top-1);
   L->top--;
   lua_unlock(L);
 }
@@ -804,16 +829,15 @@ LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) {
 
 LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {
   StkId o;
-  Table *t;
-  TValue k;
+  TValue k, *slot;
   lua_lock(L);
   api_checknelems(L, 1);
   o = index2addr(L, idx);
   api_check(L, ttistable(o), "table expected");
-  t = hvalue(o);
   setpvalue(&k, cast(void *, p));
-  setobj2t(L, luaH_set(L, t, &k), L->top - 1);
-  luaC_barrierback(L, t, L->top - 1);
+  slot = luaH_set(L, hvalue(o), &k);
+  setobj2t(L, slot, L->top - 1);
+  luaC_barrierback(L, hvalue(o), L->top - 1);
   L->top--;
   lua_unlock(L);
 }
@@ -895,10 +919,10 @@ LUA_API void lua_callk (lua_State *L, int nargs, int nresults,
   if (k != NULL && L->nny == 0) {  /* need to prepare continuation? */
     L->ci->u.c.k = k;  /* save continuation */
     L->ci->u.c.ctx = ctx;  /* save context */
-    luaD_call(L, func, nresults, 1);  /* do the call */
+    luaD_call(L, func, nresults);  /* do the call */
   }
   else  /* no continuation or no yieldable */
-    luaD_call(L, func, nresults, 0);  /* just do the call */
+    luaD_callnoyield(L, func, nresults);  /* just do the call */
   adjustresults(L, nresults);
   lua_unlock(L);
 }
@@ -916,7 +940,7 @@ struct CallS {  /* data to 'f_call' */
 
 static void f_call (lua_State *L, void *ud) {
   struct CallS *c = cast(struct CallS *, ud);
-  luaD_call(L, c->func, c->nresults, 0);
+  luaD_callnoyield(L, c->func, c->nresults);
 }
 
 
@@ -954,7 +978,7 @@ LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
     L->errfunc = func;
     setoah(ci->callstatus, L->allowhook);  /* save value of 'allowhook' */
     ci->callstatus |= CIST_YPCALL;  /* function can do error recovery */
-    luaD_call(L, c.func, nresults, 1);  /* do the call */
+    luaD_call(L, c.func, nresults);  /* do the call */
     ci->callstatus &= ~CIST_YPCALL;
     L->errfunc = ci->u.c.old_errfunc;
     status = LUA_OK;  /* if it is here, there were no errors */
@@ -1043,7 +1067,7 @@ LUA_API int lua_gc (lua_State *L, int what, int data) {
     }
     case LUA_GCSTEP: {
       l_mem debt = 1;  /* =1 to signal that it did an actual step */
-      int oldrunning = g->gcrunning;
+      lu_byte oldrunning = g->gcrunning;
       g->gcrunning = 1;  /* allow GC to run */
       if (data == 0) {
         luaE_setdebt(g, -GCSTEPSIZE);  /* to do a "small" step */
@@ -1117,7 +1141,6 @@ LUA_API void lua_concat (lua_State *L, int n) {
   lua_lock(L);
   api_checknelems(L, n);
   if (n >= 2) {
-    luaC_checkGC(L);
     luaV_concat(L, n);
   }
   else if (n == 0) {  /* push empty string */
@@ -1125,6 +1148,7 @@ LUA_API void lua_concat (lua_State *L, int n) {
     api_incr_top(L);
   }
   /* else n == 1; nothing to do */
+  luaC_checkGC(L);
   lua_unlock(L);
 }
 
@@ -1160,10 +1184,10 @@ LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) {
 LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
   Udata *u;
   lua_lock(L);
-  luaC_checkGC(L);
   u = luaS_newudata(L, size);
   setuvalue(L, L->top, u);
   api_incr_top(L);
+  luaC_checkGC(L);
   lua_unlock(L);
   return getudatamem(u);
 }
@@ -1230,13 +1254,12 @@ LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
 }
 
 
-static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) {
+static UpVal **getupvalref (lua_State *L, int fidx, int n) {
   LClosure *f;
   StkId fi = index2addr(L, fidx);
   api_check(L, ttisLclosure(fi), "Lua function expected");
   f = clLvalue(fi);
   api_check(L, (1 <= n && n <= f->p->sizeupvalues), "invalid upvalue index");
-  if (pf) *pf = f;
   return &f->upvals[n - 1];  /* get its upvalue pointer */
 }
 
@@ -1245,7 +1268,7 @@ LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) {
   StkId fi = index2addr(L, fidx);
   switch (ttype(fi)) {
     case LUA_TLCL: {  /* lua closure */
-      return *getupvalref(L, fidx, n, NULL);
+      return *getupvalref(L, fidx, n);
     }
     case LUA_TCCL: {  /* C closure */
       CClosure *f = clCvalue(fi);
@@ -1262,9 +1285,10 @@ LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) {
 
 LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
                                             int fidx2, int n2) {
-  LClosure *f1;
-  UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
-  UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
+  UpVal **up1 = getupvalref(L, fidx1, n1);
+  UpVal **up2 = getupvalref(L, fidx2, n2);
+  if (*up1 == *up2)
+    return;
   luaC_upvdeccount(L, *up1);
   *up1 = *up2;
   (*up1)->refcount++;
diff --git a/source/extern/lua/lapi.h b/source/extern/lua/lapi.h
index 6d36dee..8e16ad5 100644
--- a/source/extern/lua/lapi.h
+++ b/source/extern/lua/lapi.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.h,v 2.9 2015/03/06 19:49:50 roberto Exp $
+** $Id: lapi.h,v 2.9.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Auxiliary functions from Lua API
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/lauxlib.c b/source/extern/lua/lauxlib.c
index b8bace7..ac68bd3 100644
--- a/source/extern/lua/lauxlib.c
+++ b/source/extern/lua/lauxlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.c,v 1.280 2015/02/03 17:38:24 roberto Exp $
+** $Id: lauxlib.c,v 1.289.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -17,7 +17,8 @@
 #include <string.h>
 
 
-/* This file uses only the official API of Lua.
+/*
+** This file uses only the official API of Lua.
 ** Any function declared here could be written as an application function.
 */
 
@@ -33,8 +34,8 @@
 */
 
 
-#define LEVELS1	12	/* size of the first part of the stack */
-#define LEVELS2	10	/* size of the second part of the stack */
+#define LEVELS1	10	/* size of the first part of the stack */
+#define LEVELS2	11	/* size of the second part of the stack */
 
 
 
@@ -68,12 +69,11 @@ static int findfield (lua_State *L, int objidx, int level) {
 
 /*
 ** Search for a name for a function in all loaded modules
-** (registry._LOADED).
 */
 static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
   int top = lua_gettop(L);
   lua_getinfo(L, "f", ar);  /* push function */
-  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
+  lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
   if (findfield(L, top + 1, 2)) {
     const char *name = lua_tostring(L, -1);
     if (strncmp(name, "_G.", 3) == 0) {  /* name start with '_G.'? */
@@ -107,7 +107,7 @@ static void pushfuncname (lua_State *L, lua_Debug *ar) {
 }
 
 
-static int countlevels (lua_State *L) {
+static int lastlevel (lua_State *L) {
   lua_Debug ar;
   int li = 1, le = 1;
   /* find an upper bound */
@@ -126,14 +126,16 @@ LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
                                 const char *msg, int level) {
   lua_Debug ar;
   int top = lua_gettop(L);
-  int numlevels = countlevels(L1);
-  int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0;
-  if (msg) lua_pushfstring(L, "%s\n", msg);
+  int last = lastlevel(L1);
+  int n1 = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
+  if (msg)
+    lua_pushfstring(L, "%s\n", msg);
+  luaL_checkstack(L, 10, NULL);
   lua_pushliteral(L, "stack traceback:");
   while (lua_getstack(L1, level++, &ar)) {
-    if (level == mark) {  /* too many levels? */
+    if (n1-- == 0) {  /* too many levels? */
       lua_pushliteral(L, "\n\t...");  /* add a '...' */
-      level = numlevels - LEVELS2;  /* and skip to last ones */
+      level = last - LEVELS2 + 1;  /* and skip to last ones */
     }
     else {
       lua_getinfo(L1, "Slnt", &ar);
@@ -196,6 +198,10 @@ static void tag_error (lua_State *L, int arg, int tag) {
 }
 
 
+/*
+** The use of 'lua_pushfstring' ensures this function does not
+** need reserved stack space when called.
+*/
 LUALIB_API void luaL_where (lua_State *L, int level) {
   lua_Debug ar;
   if (lua_getstack(L, level, &ar)) {  /* check function at level */
@@ -205,10 +211,15 @@ LUALIB_API void luaL_where (lua_State *L, int level) {
       return;
     }
   }
-  lua_pushliteral(L, "");  /* else, no information available... */
+  lua_pushfstring(L, "");  /* else, no information available... */
 }
 
 
+/*
+** Again, the use of 'lua_pushvfstring' ensures this function does
+** not need reserved stack space when called. (At worst, it generates
+** an error with "stack overflow" instead of the given message.)
+*/
 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
   va_list argp;
   va_start(argp, fmt);
@@ -289,7 +300,7 @@ LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
   if (luaL_getmetatable(L, tname) != LUA_TNIL)  /* name already in use? */
     return 0;  /* leave previous value on top, but return 0 */
   lua_pop(L, 1);
-  lua_newtable(L);  /* create metatable */
+  lua_createtable(L, 0, 2);  /* create metatable */
   lua_pushstring(L, tname);
   lua_setfield(L, -2, "__name");  /* metatable.__name = tname */
   lua_pushvalue(L, -1);
@@ -347,10 +358,15 @@ LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,
 }
 
 
+/*
+** Ensures the stack has at least 'space' extra slots, raising an error
+** if it cannot fulfill the request. (The error handling needs a few
+** extra slots to format the error message. In case of an error without
+** this extra space, Lua will generate the same 'stack overflow' error,
+** but without 'msg'.)
+*/
 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
-  /* keep some extra space to run error routines, if needed */
-  const int extra = LUA_MINSTACK;
-  if (!lua_checkstack(L, space + extra)) {
+  if (!lua_checkstack(L, space)) {
     if (msg)
       luaL_error(L, "stack overflow (%s)", msg);
     else
@@ -435,6 +451,47 @@ LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg,
 ** =======================================================
 */
 
+/* userdata to box arbitrary data */
+typedef struct UBox {
+  void *box;
+  size_t bsize;
+} UBox;
+
+
+static void *resizebox (lua_State *L, int idx, size_t newsize) {
+  void *ud;
+  lua_Alloc allocf = lua_getallocf(L, &ud);
+  UBox *box = (UBox *)lua_touserdata(L, idx);
+  void *temp = allocf(ud, box->box, box->bsize, newsize);
+  if (temp == NULL && newsize > 0) {  /* allocation error? */
+    resizebox(L, idx, 0);  /* free buffer */
+    luaL_error(L, "not enough memory for buffer allocation");
+  }
+  box->box = temp;
+  box->bsize = newsize;
+  return temp;
+}
+
+
+static int boxgc (lua_State *L) {
+  resizebox(L, 1, 0);
+  return 0;
+}
+
+
+static void *newbox (lua_State *L, size_t newsize) {
+  UBox *box = (UBox *)lua_newuserdata(L, sizeof(UBox));
+  box->box = NULL;
+  box->bsize = 0;
+  if (luaL_newmetatable(L, "LUABOX")) {  /* creating metatable? */
+    lua_pushcfunction(L, boxgc);
+    lua_setfield(L, -2, "__gc");  /* metatable.__gc = boxgc */
+  }
+  lua_setmetatable(L, -2);
+  return resizebox(L, -1, newsize);
+}
+
+
 /*
 ** check whether buffer is using a userdata on the stack as a temporary
 ** buffer
@@ -455,11 +512,12 @@ LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
     if (newsize < B->n || newsize - B->n < sz)
       luaL_error(L, "buffer too large");
     /* create larger buffer */
-    newbuff = (char *)lua_newuserdata(L, newsize * sizeof(char));
-    /* move content to new buffer */
-    memcpy(newbuff, B->b, B->n * sizeof(char));
     if (buffonstack(B))
-      lua_remove(L, -2);  /* remove old buffer */
+      newbuff = (char *)resizebox(L, -1, newsize);
+    else {  /* no buffer yet */
+      newbuff = (char *)newbox(L, newsize);
+      memcpy(newbuff, B->b, B->n * sizeof(char));  /* copy original content */
+    }
     B->b = newbuff;
     B->size = newsize;
   }
@@ -468,9 +526,11 @@ LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
 
 
 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
-  char *b = luaL_prepbuffsize(B, l);
-  memcpy(b, s, l * sizeof(char));
-  luaL_addsize(B, l);
+  if (l > 0) {  /* avoid 'memcpy' when 's' can be NULL */
+    char *b = luaL_prepbuffsize(B, l);
+    memcpy(b, s, l * sizeof(char));
+    luaL_addsize(B, l);
+  }
 }
 
 
@@ -482,8 +542,10 @@ LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
   lua_State *L = B->L;
   lua_pushlstring(L, B->b, B->n);
-  if (buffonstack(B))
-    lua_remove(L, -2);  /* remove old buffer */
+  if (buffonstack(B)) {
+    resizebox(L, -2, 0);  /* delete old buffer */
+    lua_remove(L, -2);  /* remove its header from the stack */
+  }
 }
 
 
@@ -605,7 +667,7 @@ static int errfile (lua_State *L, const char *what, int fnameindex) {
 
 
 static int skipBOM (LoadF *lf) {
-  const char *p = "\xEF\xBB\xBF";  /* Utf8 BOM mark */
+  const char *p = "\xEF\xBB\xBF";  /* UTF-8 BOM mark */
   int c;
   lf->n = 0;
   do {
@@ -630,7 +692,7 @@ static int skipcomment (LoadF *lf, int *cp) {
   if (c == '#') {  /* first line is a comment (Unix exec. file)? */
     do {  /* skip first line */
       c = getc(lf->f);
-    } while (c != EOF && c != '\n') ;
+    } while (c != EOF && c != '\n');
     *cp = getc(lf->f);  /* skip end-of-line, if present */
     return 1;  /* there was a comment */
   }
@@ -746,13 +808,17 @@ LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
 
 
 LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
-  if (!luaL_callmeta(L, idx, "__tostring")) {  /* no metafield? */
+  if (luaL_callmeta(L, idx, "__tostring")) {  /* metafield? */
+    if (!lua_isstring(L, -1))
+      luaL_error(L, "'__tostring' must return a string");
+  }
+  else {
     switch (lua_type(L, idx)) {
       case LUA_TNUMBER: {
         if (lua_isinteger(L, idx))
-          lua_pushfstring(L, "%I", lua_tointeger(L, idx));
+          lua_pushfstring(L, "%I", (LUAI_UACINT)lua_tointeger(L, idx));
         else
-          lua_pushfstring(L, "%f", lua_tonumber(L, idx));
+          lua_pushfstring(L, "%f", (LUAI_UACNUMBER)lua_tonumber(L, idx));
         break;
       }
       case LUA_TSTRING:
@@ -764,10 +830,15 @@ LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
       case LUA_TNIL:
         lua_pushliteral(L, "nil");
         break;
-      default:
-        lua_pushfstring(L, "%s: %p", luaL_typename(L, idx),
-                                            lua_topointer(L, idx));
+      default: {
+        int tt = luaL_getmetafield(L, idx, "__name");  /* try name */
+        const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) :
+                                                 luaL_typename(L, idx);
+        lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx));
+        if (tt != LUA_TNIL)
+          lua_remove(L, -2);  /* remove '__name' */
         break;
+      }
     }
   }
   return lua_tolstring(L, -1, len);
@@ -819,23 +890,23 @@ static int libsize (const luaL_Reg *l) {
 
 /*
 ** Find or create a module table with a given name. The function
-** first looks at the _LOADED table and, if that fails, try a
+** first looks at the LOADED table and, if that fails, try a
 ** global variable with that name. In any case, leaves on the stack
 ** the module table.
 */
 LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname,
                                  int sizehint) {
-  luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);  /* get _LOADED table */
-  if (lua_getfield(L, -1, modname) != LUA_TTABLE) {  /* no _LOADED[modname]? */
+  luaL_findtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE, 1);
+  if (lua_getfield(L, -1, modname) != LUA_TTABLE) {  /* no LOADED[modname]? */
     lua_pop(L, 1);  /* remove previous result */
     /* try global variable (and create one if it does not exist) */
     lua_pushglobaltable(L);
     if (luaL_findtable(L, 0, modname, sizehint) != NULL)
       luaL_error(L, "name conflict for module '%s'", modname);
     lua_pushvalue(L, -1);
-    lua_setfield(L, -3, modname);  /* _LOADED[modname] = new table */
+    lua_setfield(L, -3, modname);  /* LOADED[modname] = new table */
   }
-  lua_remove(L, -2);  /* remove _LOADED table */
+  lua_remove(L, -2);  /* remove LOADED table */
 }
 
 
@@ -899,17 +970,17 @@ LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
 */
 LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
                                lua_CFunction openf, int glb) {
-  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
-  lua_getfield(L, -1, modname);  /* _LOADED[modname] */
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
+  lua_getfield(L, -1, modname);  /* LOADED[modname] */
   if (!lua_toboolean(L, -1)) {  /* package not already loaded? */
     lua_pop(L, 1);  /* remove field */
     lua_pushcfunction(L, openf);
     lua_pushstring(L, modname);  /* argument to open function */
     lua_call(L, 1, 1);  /* call 'openf' to open module */
     lua_pushvalue(L, -1);  /* make copy of module (call result) */
-    lua_setfield(L, -3, modname);  /* _LOADED[modname] = module */
+    lua_setfield(L, -3, modname);  /* LOADED[modname] = module */
   }
-  lua_remove(L, -2);  /* remove _LOADED table */
+  lua_remove(L, -2);  /* remove LOADED table */
   if (glb) {
     lua_pushvalue(L, -1);  /* copy of module */
     lua_setglobal(L, modname);  /* _G[modname] = module */
@@ -940,8 +1011,13 @@ static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
     free(ptr);
     return NULL;
   }
-  else
-    return realloc(ptr, nsize);
+  else {  /* cannot fail when shrinking a block */
+    void *newptr = realloc(ptr, nsize);
+    if (newptr == NULL && ptr != NULL && nsize <= osize)
+      return ptr;  /* keep the original block */
+    else  /* no fail or not shrinking */
+     return newptr;  /* use the new block */
+  }
 }
 
 
@@ -967,6 +1043,6 @@ LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) {
     luaL_error(L, "multiple Lua VMs detected");
   else if (*v != ver)
     luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
-                  ver, *v);
+                  (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)*v);
 }
 
diff --git a/source/extern/lua/lbaselib.c b/source/extern/lua/lbaselib.c
index 9a15124..6460e4f 100644
--- a/source/extern/lua/lbaselib.c
+++ b/source/extern/lua/lbaselib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lbaselib.c,v 1.310 2015/03/28 19:14:47 roberto Exp $
+** $Id: lbaselib.c,v 1.314.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Basic library
 ** See Copyright Notice in lua.h
 */
@@ -86,8 +86,8 @@ static int luaB_tonumber (lua_State *L) {
     const char *s;
     lua_Integer n = 0;  /* to avoid warnings */
     lua_Integer base = luaL_checkinteger(L, 2);
-    luaL_checktype(L, 1, LUA_TSTRING);  /* before 'luaL_checklstring'! */
-    s = luaL_checklstring(L, 1, &l);
+    luaL_checktype(L, 1, LUA_TSTRING);  /* no numbers as strings */
+    s = lua_tolstring(L, 1, &l);
     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
     if (b_str2int(s, (int)base, &n) == s + l) {
       lua_pushinteger(L, n);
@@ -102,8 +102,8 @@ static int luaB_tonumber (lua_State *L) {
 static int luaB_error (lua_State *L) {
   int level = (int)luaL_optinteger(L, 2, 1);
   lua_settop(L, 1);
-  if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
-    luaL_where(L, level);
+  if (lua_type(L, 1) == LUA_TSTRING && level > 0) {
+    luaL_where(L, level);   /* add extra information */
     lua_pushvalue(L, 1);
     lua_concat(L, 2);
   }
@@ -198,20 +198,18 @@ static int luaB_collectgarbage (lua_State *L) {
 }
 
 
-/*
-** This function has all type names as upvalues, to maximize performance.
-*/
 static int luaB_type (lua_State *L) {
-  luaL_checkany(L, 1);
-  lua_pushvalue(L, lua_upvalueindex(lua_type(L, 1) + 1));
+  int t = lua_type(L, 1);
+  luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
+  lua_pushstring(L, lua_typename(L, t));
   return 1;
 }
 
 
 static int pairsmeta (lua_State *L, const char *method, int iszero,
                       lua_CFunction iter) {
+  luaL_checkany(L, 1);
   if (luaL_getmetafield(L, 1, method) == LUA_TNIL) {  /* no metamethod? */
-    luaL_checktype(L, 1, LUA_TTABLE);  /* argument must be a table */
     lua_pushcfunction(L, iter);  /* will return generator, */
     lua_pushvalue(L, 1);  /* state, */
     if (iszero) lua_pushinteger(L, 0);  /* and initial value */
@@ -243,18 +241,7 @@ static int luaB_pairs (lua_State *L) {
 
 
 /*
-** Traversal function for 'ipairs' for raw tables
-*/
-static int ipairsaux_raw (lua_State *L) {
-  lua_Integer i = luaL_checkinteger(L, 2) + 1;
-  luaL_checktype(L, 1, LUA_TTABLE);
-  lua_pushinteger(L, i);
-  return (lua_rawgeti(L, 1, i) == LUA_TNIL) ? 1 : 2;
-}
-
-
-/*
-** Traversal function for 'ipairs' for tables with metamethods
+** Traversal function for 'ipairs'
 */
 static int ipairsaux (lua_State *L) {
   lua_Integer i = luaL_checkinteger(L, 2) + 1;
@@ -264,18 +251,15 @@ static int ipairsaux (lua_State *L) {
 
 
 /*
-** This function will use either 'ipairsaux' or 'ipairsaux_raw' to
-** traverse a table, depending on whether the table has metamethods
-** that can affect the traversal.
+** 'ipairs' function. Returns 'ipairsaux', given "table", 0.
+** (The given "table" may not be a table.)
 */
 static int luaB_ipairs (lua_State *L) {
-  lua_CFunction iter = (luaL_getmetafield(L, 1, "__index") != LUA_TNIL)
-                       ? ipairsaux : ipairsaux_raw;
 #if defined(LUA_COMPAT_IPAIRS)
-  return pairsmeta(L, "__ipairs", 1, iter);
+  return pairsmeta(L, "__ipairs", 1, ipairsaux);
 #else
   luaL_checkany(L, 1);
-  lua_pushcfunction(L, iter);  /* iteration function */
+  lua_pushcfunction(L, ipairsaux);  /* iteration function */
   lua_pushvalue(L, 1);  /* state */
   lua_pushinteger(L, 0);  /* initial value */
   return 3;
@@ -490,9 +474,9 @@ static const luaL_Reg base_funcs[] = {
   {"setmetatable", luaB_setmetatable},
   {"tonumber", luaB_tonumber},
   {"tostring", luaB_tostring},
+  {"type", luaB_type},
   {"xpcall", luaB_xpcall},
   /* placeholders */
-  {"type", NULL},
   {"_G", NULL},
   {"_VERSION", NULL},
   {NULL, NULL}
@@ -500,7 +484,6 @@ static const luaL_Reg base_funcs[] = {
 
 
 LUAMOD_API int luaopen_base (lua_State *L) {
-  int i;
   /* open lib into global table */
   lua_pushglobaltable(L);
   luaL_setfuncs(L, base_funcs, 0);
@@ -510,11 +493,6 @@ LUAMOD_API int luaopen_base (lua_State *L) {
   /* set global _VERSION */
   lua_pushliteral(L, LUA_VERSION);
   lua_setfield(L, -2, "_VERSION");
-  /* set function 'type' with proper upvalues */
-  for (i = 0; i < LUA_NUMTAGS; i++)  /* push all type names as upvalues */
-    lua_pushstring(L, lua_typename(L, i));
-  lua_pushcclosure(L, luaB_type, LUA_NUMTAGS);
-  lua_setfield(L, -2, "type");
   return 1;
 }
 
diff --git a/source/extern/lua/lbitlib.c b/source/extern/lua/lbitlib.c
index 15d5f0c..4786c0d 100644
--- a/source/extern/lua/lbitlib.c
+++ b/source/extern/lua/lbitlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lbitlib.c,v 1.28 2014/11/02 19:19:04 roberto Exp $
+** $Id: lbitlib.c,v 1.30.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Standard library for bitwise operations
 ** See Copyright Notice in lua.h
 */
@@ -19,6 +19,10 @@
 #if defined(LUA_COMPAT_BITLIB)		/* { */
 
 
+#define pushunsigned(L,n)	lua_pushinteger(L, (lua_Integer)(n))
+#define checkunsigned(L,i)	((lua_Unsigned)luaL_checkinteger(L,i))
+
+
 /* number of bits to consider in a number */
 #if !defined(LUA_NBITS)
 #define LUA_NBITS	32
@@ -46,14 +50,14 @@ static lua_Unsigned andaux (lua_State *L) {
   int i, n = lua_gettop(L);
   lua_Unsigned r = ~(lua_Unsigned)0;
   for (i = 1; i <= n; i++)
-    r &= luaL_checkunsigned(L, i);
+    r &= checkunsigned(L, i);
   return trim(r);
 }
 
 
 static int b_and (lua_State *L) {
   lua_Unsigned r = andaux(L);
-  lua_pushunsigned(L, r);
+  pushunsigned(L, r);
   return 1;
 }
 
@@ -69,8 +73,8 @@ static int b_or (lua_State *L) {
   int i, n = lua_gettop(L);
   lua_Unsigned r = 0;
   for (i = 1; i <= n; i++)
-    r |= luaL_checkunsigned(L, i);
-  lua_pushunsigned(L, trim(r));
+    r |= checkunsigned(L, i);
+  pushunsigned(L, trim(r));
   return 1;
 }
 
@@ -79,15 +83,15 @@ static int b_xor (lua_State *L) {
   int i, n = lua_gettop(L);
   lua_Unsigned r = 0;
   for (i = 1; i <= n; i++)
-    r ^= luaL_checkunsigned(L, i);
-  lua_pushunsigned(L, trim(r));
+    r ^= checkunsigned(L, i);
+  pushunsigned(L, trim(r));
   return 1;
 }
 
 
 static int b_not (lua_State *L) {
-  lua_Unsigned r = ~luaL_checkunsigned(L, 1);
-  lua_pushunsigned(L, trim(r));
+  lua_Unsigned r = ~checkunsigned(L, 1);
+  pushunsigned(L, trim(r));
   return 1;
 }
 
@@ -104,23 +108,23 @@ static int b_shift (lua_State *L, lua_Unsigned r, lua_Integer i) {
     else r <<= i;
     r = trim(r);
   }
-  lua_pushunsigned(L, r);
+  pushunsigned(L, r);
   return 1;
 }
 
 
 static int b_lshift (lua_State *L) {
-  return b_shift(L, luaL_checkunsigned(L, 1), luaL_checkinteger(L, 2));
+  return b_shift(L, checkunsigned(L, 1), luaL_checkinteger(L, 2));
 }
 
 
 static int b_rshift (lua_State *L) {
-  return b_shift(L, luaL_checkunsigned(L, 1), -luaL_checkinteger(L, 2));
+  return b_shift(L, checkunsigned(L, 1), -luaL_checkinteger(L, 2));
 }
 
 
 static int b_arshift (lua_State *L) {
-  lua_Unsigned r = luaL_checkunsigned(L, 1);
+  lua_Unsigned r = checkunsigned(L, 1);
   lua_Integer i = luaL_checkinteger(L, 2);
   if (i < 0 || !(r & ((lua_Unsigned)1 << (LUA_NBITS - 1))))
     return b_shift(L, r, -i);
@@ -128,19 +132,19 @@ static int b_arshift (lua_State *L) {
     if (i >= LUA_NBITS) r = ALLONES;
     else
       r = trim((r >> i) | ~(trim(~(lua_Unsigned)0) >> i));  /* add signal bit */
-    lua_pushunsigned(L, r);
+    pushunsigned(L, r);
     return 1;
   }
 }
 
 
 static int b_rot (lua_State *L, lua_Integer d) {
-  lua_Unsigned r = luaL_checkunsigned(L, 1);
+  lua_Unsigned r = checkunsigned(L, 1);
   int i = d & (LUA_NBITS - 1);  /* i = d % NBITS */
   r = trim(r);
   if (i != 0)  /* avoid undefined shift of LUA_NBITS when i == 0 */
     r = (r << i) | (r >> (LUA_NBITS - i));
-  lua_pushunsigned(L, trim(r));
+  pushunsigned(L, trim(r));
   return 1;
 }
 
@@ -175,23 +179,22 @@ static int fieldargs (lua_State *L, int farg, int *width) {
 
 static int b_extract (lua_State *L) {
   int w;
-  lua_Unsigned r = trim(luaL_checkunsigned(L, 1));
+  lua_Unsigned r = trim(checkunsigned(L, 1));
   int f = fieldargs(L, 2, &w);
   r = (r >> f) & mask(w);
-  lua_pushunsigned(L, r);
+  pushunsigned(L, r);
   return 1;
 }
 
 
 static int b_replace (lua_State *L) {
   int w;
-  lua_Unsigned r = trim(luaL_checkunsigned(L, 1));
-  lua_Unsigned v = luaL_checkunsigned(L, 2);
+  lua_Unsigned r = trim(checkunsigned(L, 1));
+  lua_Unsigned v = trim(checkunsigned(L, 2));
   int f = fieldargs(L, 3, &w);
-  int m = mask(w);
-  v &= m;  /* erase bits outside given width */
-  r = (r & ~(m << f)) | (v << f);
-  lua_pushunsigned(L, r);
+  lua_Unsigned m = mask(w);
+  r = (r & ~(m << f)) | ((v & m) << f);
+  pushunsigned(L, r);
   return 1;
 }
 
diff --git a/source/extern/lua/lcode.c b/source/extern/lua/lcode.c
index d6f0fcd..dc7271d 100644
--- a/source/extern/lua/lcode.c
+++ b/source/extern/lua/lcode.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.c,v 2.101 2015/04/29 18:24:11 roberto Exp $
+** $Id: lcode.c,v 2.112.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -36,8 +36,12 @@
 #define hasjumps(e)	((e)->t != (e)->f)
 
 
-static int tonumeral(expdesc *e, TValue *v) {
-  if (e->t != NO_JUMP || e->f != NO_JUMP)
+/*
+** If expression is a numeric constant, fills 'v' with its value
+** and returns 1. Otherwise, returns 0.
+*/
+static int tonumeral(const expdesc *e, TValue *v) {
+  if (hasjumps(e))
     return 0;  /* not a numeral */
   switch (e->k) {
     case VKINT:
@@ -51,13 +55,19 @@ static int tonumeral(expdesc *e, TValue *v) {
 }
 
 
+/*
+** Create a OP_LOADNIL instruction, but try to optimize: if the previous
+** instruction is also OP_LOADNIL and ranges are compatible, adjust
+** range of previous instruction instead of emitting a new one. (For
+** instance, 'local a; local b' will generate a single opcode.)
+*/
 void luaK_nil (FuncState *fs, int from, int n) {
   Instruction *previous;
   int l = from + n - 1;  /* last register to set nil */
   if (fs->pc > fs->lasttarget) {  /* no jumps to current position? */
     previous = &fs->f->code[fs->pc-1];
-    if (GET_OPCODE(*previous) == OP_LOADNIL) {
-      int pfrom = GETARG_A(*previous);
+    if (GET_OPCODE(*previous) == OP_LOADNIL) {  /* previous is LOADNIL? */
+      int pfrom = GETARG_A(*previous);  /* get previous range */
       int pl = pfrom + GETARG_B(*previous);
       if ((pfrom <= from && from <= pl + 1) ||
           (from <= pfrom && pfrom <= l + 1)) {  /* can connect both? */
@@ -73,37 +83,84 @@ void luaK_nil (FuncState *fs, int from, int n) {
 }
 
 
+/*
+** Gets the destination address of a jump instruction. Used to traverse
+** a list of jumps.
+*/
+static int getjump (FuncState *fs, int pc) {
+  int offset = GETARG_sBx(fs->f->code[pc]);
+  if (offset == NO_JUMP)  /* point to itself represents end of list */
+    return NO_JUMP;  /* end of list */
+  else
+    return (pc+1)+offset;  /* turn offset into absolute position */
+}
+
+
+/*
+** Fix jump instruction at position 'pc' to jump to 'dest'.
+** (Jump addresses are relative in Lua)
+*/
+static void fixjump (FuncState *fs, int pc, int dest) {
+  Instruction *jmp = &fs->f->code[pc];
+  int offset = dest - (pc + 1);
+  lua_assert(dest != NO_JUMP);
+  if (abs(offset) > MAXARG_sBx)
+    luaX_syntaxerror(fs->ls, "control structure too long");
+  SETARG_sBx(*jmp, offset);
+}
+
+
+/*
+** Concatenate jump-list 'l2' into jump-list 'l1'
+*/
+void luaK_concat (FuncState *fs, int *l1, int l2) {
+  if (l2 == NO_JUMP) return;  /* nothing to concatenate? */
+  else if (*l1 == NO_JUMP)  /* no original list? */
+    *l1 = l2;  /* 'l1' points to 'l2' */
+  else {
+    int list = *l1;
+    int next;
+    while ((next = getjump(fs, list)) != NO_JUMP)  /* find last element */
+      list = next;
+    fixjump(fs, list, l2);  /* last element links to 'l2' */
+  }
+}
+
+
+/*
+** Create a jump instruction and return its position, so its destination
+** can be fixed later (with 'fixjump'). If there are jumps to
+** this position (kept in 'jpc'), link them all together so that
+** 'patchlistaux' will fix all them directly to the final destination.
+*/
 int luaK_jump (FuncState *fs) {
   int jpc = fs->jpc;  /* save list of jumps to here */
   int j;
-  fs->jpc = NO_JUMP;
+  fs->jpc = NO_JUMP;  /* no more jumps to here */
   j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
   luaK_concat(fs, &j, jpc);  /* keep them on hold */
   return j;
 }
 
 
+/*
+** Code a 'return' instruction
+*/
 void luaK_ret (FuncState *fs, int first, int nret) {
   luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
 }
 
 
+/*
+** Code a "conditional jump", that is, a test or comparison opcode
+** followed by a jump. Return jump position.
+*/
 static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {
   luaK_codeABC(fs, op, A, B, C);
   return luaK_jump(fs);
 }
 
 
-static void fixjump (FuncState *fs, int pc, int dest) {
-  Instruction *jmp = &fs->f->code[pc];
-  int offset = dest-(pc+1);
-  lua_assert(dest != NO_JUMP);
-  if (abs(offset) > MAXARG_sBx)
-    luaX_syntaxerror(fs->ls, "control structure too long");
-  SETARG_sBx(*jmp, offset);
-}
-
-
 /*
 ** returns current 'pc' and marks it as a jump target (to avoid wrong
 ** optimizations with consecutive instructions not in the same basic block).
@@ -114,15 +171,11 @@ int luaK_getlabel (FuncState *fs) {
 }
 
 
-static int getjump (FuncState *fs, int pc) {
-  int offset = GETARG_sBx(fs->f->code[pc]);
-  if (offset == NO_JUMP)  /* point to itself represents end of list */
-    return NO_JUMP;  /* end of list */
-  else
-    return (pc+1)+offset;  /* turn offset into absolute position */
-}
-
-
+/*
+** Returns the position of the instruction "controlling" a given
+** jump (that is, its condition), or the jump itself if it is
+** unconditional.
+*/
 static Instruction *getjumpcontrol (FuncState *fs, int pc) {
   Instruction *pi = &fs->f->code[pc];
   if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1))))
@@ -133,37 +186,41 @@ static Instruction *getjumpcontrol (FuncState *fs, int pc) {
 
 
 /*
-** check whether list has any jump that do not produce a value
-** (or produce an inverted value)
+** Patch destination register for a TESTSET instruction.
+** If instruction in position 'node' is not a TESTSET, return 0 ("fails").
+** Otherwise, if 'reg' is not 'NO_REG', set it as the destination
+** register. Otherwise, change instruction to a simple 'TEST' (produces
+** no register value)
 */
-static int need_value (FuncState *fs, int list) {
-  for (; list != NO_JUMP; list = getjump(fs, list)) {
-    Instruction i = *getjumpcontrol(fs, list);
-    if (GET_OPCODE(i) != OP_TESTSET) return 1;
-  }
-  return 0;  /* not found */
-}
-
-
 static int patchtestreg (FuncState *fs, int node, int reg) {
   Instruction *i = getjumpcontrol(fs, node);
   if (GET_OPCODE(*i) != OP_TESTSET)
     return 0;  /* cannot patch other instructions */
   if (reg != NO_REG && reg != GETARG_B(*i))
     SETARG_A(*i, reg);
-  else  /* no register to put value or register already has the value */
+  else {
+     /* no register to put value or register already has the value;
+        change instruction to simple test */
     *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));
-
+  }
   return 1;
 }
 
 
+/*
+** Traverse a list of tests ensuring no one produces a value
+*/
 static void removevalues (FuncState *fs, int list) {
   for (; list != NO_JUMP; list = getjump(fs, list))
       patchtestreg(fs, list, NO_REG);
 }
 
 
+/*
+** Traverse a list of tests, patching their destination address and
+** registers: tests producing values jump to 'vtarget' (and put their
+** values in 'reg'), other tests jump to 'dtarget'.
+*/
 static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
                           int dtarget) {
   while (list != NO_JUMP) {
@@ -177,15 +234,35 @@ static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
 }
 
 
+/*
+** Ensure all pending jumps to current position are fixed (jumping
+** to current position with no values) and reset list of pending
+** jumps
+*/
 static void dischargejpc (FuncState *fs) {
   patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
   fs->jpc = NO_JUMP;
 }
 
 
+/*
+** Add elements in 'list' to list of pending jumps to "here"
+** (current position)
+*/
+void luaK_patchtohere (FuncState *fs, int list) {
+  luaK_getlabel(fs);  /* mark "here" as a jump target */
+  luaK_concat(fs, &fs->jpc, list);
+}
+
+
+/*
+** Path all jumps in 'list' to jump to 'target'.
+** (The assert means that we cannot fix a jump to a forward address
+** because we only know addresses once code is generated.)
+*/
 void luaK_patchlist (FuncState *fs, int list, int target) {
-  if (target == fs->pc)
-    luaK_patchtohere(fs, list);
+  if (target == fs->pc)  /* 'target' is current position? */
+    luaK_patchtohere(fs, list);  /* add list to pending jumps */
   else {
     lua_assert(target < fs->pc);
     patchlistaux(fs, list, target, NO_REG, target);
@@ -193,39 +270,26 @@ void luaK_patchlist (FuncState *fs, int list, int target) {
 }
 
 
+/*
+** Path all jumps in 'list' to close upvalues up to given 'level'
+** (The assertion checks that jumps either were closing nothing
+** or were closing higher levels, from inner blocks.)
+*/
 void luaK_patchclose (FuncState *fs, int list, int level) {
   level++;  /* argument is +1 to reserve 0 as non-op */
-  while (list != NO_JUMP) {
-    int next = getjump(fs, list);
+  for (; list != NO_JUMP; list = getjump(fs, list)) {
     lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP &&
                 (GETARG_A(fs->f->code[list]) == 0 ||
                  GETARG_A(fs->f->code[list]) >= level));
     SETARG_A(fs->f->code[list], level);
-    list = next;
-  }
-}
-
-
-void luaK_patchtohere (FuncState *fs, int list) {
-  luaK_getlabel(fs);
-  luaK_concat(fs, &fs->jpc, list);
-}
-
-
-void luaK_concat (FuncState *fs, int *l1, int l2) {
-  if (l2 == NO_JUMP) return;
-  else if (*l1 == NO_JUMP)
-    *l1 = l2;
-  else {
-    int list = *l1;
-    int next;
-    while ((next = getjump(fs, list)) != NO_JUMP)  /* find last element */
-      list = next;
-    fixjump(fs, list, l2);
   }
 }
 
 
+/*
+** Emit instruction 'i', checking for array sizes and saving also its
+** line information. Return 'i' position.
+*/
 static int luaK_code (FuncState *fs, Instruction i) {
   Proto *f = fs->f;
   dischargejpc(fs);  /* 'pc' will change */
@@ -241,6 +305,10 @@ static int luaK_code (FuncState *fs, Instruction i) {
 }
 
 
+/*
+** Format and emit an 'iABC' instruction. (Assertions check consistency
+** of parameters versus opcode.)
+*/
 int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
   lua_assert(getOpMode(o) == iABC);
   lua_assert(getBMode(o) != OpArgN || b == 0);
@@ -250,6 +318,9 @@ int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
 }
 
 
+/*
+** Format and emit an 'iABx' instruction.
+*/
 int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
   lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
   lua_assert(getCMode(o) == OpArgN);
@@ -258,12 +329,20 @@ int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
 }
 
 
+/*
+** Emit an "extra argument" instruction (format 'iAx')
+*/
 static int codeextraarg (FuncState *fs, int a) {
   lua_assert(a <= MAXARG_Ax);
   return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a));
 }
 
 
+/*
+** Emit a "load constant" instruction, using either 'OP_LOADK'
+** (if constant index 'k' fits in 18 bits) or an 'OP_LOADKX'
+** instruction with "extra argument".
+*/
 int luaK_codek (FuncState *fs, int reg, int k) {
   if (k <= MAXARG_Bx)
     return luaK_codeABx(fs, OP_LOADK, reg, k);
@@ -275,6 +354,10 @@ int luaK_codek (FuncState *fs, int reg, int k) {
 }
 
 
+/*
+** Check register-stack level, keeping track of its maximum size
+** in field 'maxstacksize'
+*/
 void luaK_checkstack (FuncState *fs, int n) {
   int newstack = fs->freereg + n;
   if (newstack > fs->f->maxstacksize) {
@@ -286,12 +369,20 @@ void luaK_checkstack (FuncState *fs, int n) {
 }
 
 
+/*
+** Reserve 'n' registers in register stack
+*/
 void luaK_reserveregs (FuncState *fs, int n) {
   luaK_checkstack(fs, n);
   fs->freereg += n;
 }
 
 
+/*
+** Free register 'reg', if it is neither a constant index nor
+** a local variable.
+)
+*/
 static void freereg (FuncState *fs, int reg) {
   if (!ISK(reg) && reg >= fs->nactvar) {
     fs->freereg--;
@@ -300,6 +391,9 @@ static void freereg (FuncState *fs, int reg) {
 }
 
 
+/*
+** Free register used by expression 'e' (if any)
+*/
 static void freeexp (FuncState *fs, expdesc *e) {
   if (e->k == VNONRELOC)
     freereg(fs, e->u.info);
@@ -307,8 +401,29 @@ static void freeexp (FuncState *fs, expdesc *e) {
 
 
 /*
+** Free registers used by expressions 'e1' and 'e2' (if any) in proper
+** order.
+*/
+static void freeexps (FuncState *fs, expdesc *e1, expdesc *e2) {
+  int r1 = (e1->k == VNONRELOC) ? e1->u.info : -1;
+  int r2 = (e2->k == VNONRELOC) ? e2->u.info : -1;
+  if (r1 > r2) {
+    freereg(fs, r1);
+    freereg(fs, r2);
+  }
+  else {
+    freereg(fs, r2);
+    freereg(fs, r1);
+  }
+}
+
+
+/*
+** Add constant 'v' to prototype's list of constants (field 'k').
 ** Use scanner's table to cache position of constants in constant list
-** and try to reuse constants
+** and try to reuse constants. Because some values should not be used
+** as keys (nil cannot be a key, integer keys can collapse with float
+** keys), the caller must provide a useful 'key' for indexing the cache.
 */
 static int addk (FuncState *fs, TValue *key, TValue *v) {
   lua_State *L = fs->ls->L;
@@ -337,17 +452,21 @@ static int addk (FuncState *fs, TValue *key, TValue *v) {
 }
 
 
+/*
+** Add a string to list of constants and return its index.
+*/
 int luaK_stringK (FuncState *fs, TString *s) {
   TValue o;
   setsvalue(fs->ls->L, &o, s);
-  return addk(fs, &o, &o);
+  return addk(fs, &o, &o);  /* use string itself as key */
 }
 
 
 /*
-** Integers use userdata as keys to avoid collision with floats with same
-** value; conversion to 'void*' used only for hashing, no "precision"
-** problems
+** Add an integer to list of constants and return its index.
+** Integers use userdata as keys to avoid collision with floats with
+** same value; conversion to 'void*' is used only for hashing, so there
+** are no "precision" problems.
 */
 int luaK_intK (FuncState *fs, lua_Integer n) {
   TValue k, o;
@@ -356,21 +475,29 @@ int luaK_intK (FuncState *fs, lua_Integer n) {
   return addk(fs, &k, &o);
 }
 
-
+/*
+** Add a float to list of constants and return its index.
+*/
 static int luaK_numberK (FuncState *fs, lua_Number r) {
   TValue o;
   setfltvalue(&o, r);
-  return addk(fs, &o, &o);
+  return addk(fs, &o, &o);  /* use number itself as key */
 }
 
 
+/*
+** Add a boolean to list of constants and return its index.
+*/
 static int boolK (FuncState *fs, int b) {
   TValue o;
   setbvalue(&o, b);
-  return addk(fs, &o, &o);
+  return addk(fs, &o, &o);  /* use boolean itself as key */
 }
 
 
+/*
+** Add nil to list of constants and return its index.
+*/
 static int nilK (FuncState *fs) {
   TValue k, v;
   setnilvalue(&v);
@@ -380,54 +507,79 @@ static int nilK (FuncState *fs) {
 }
 
 
+/*
+** Fix an expression to return the number of results 'nresults'.
+** Either 'e' is a multi-ret expression (function call or vararg)
+** or 'nresults' is LUA_MULTRET (as any expression can satisfy that).
+*/
 void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
   if (e->k == VCALL) {  /* expression is an open function call? */
-    SETARG_C(getcode(fs, e), nresults+1);
+    SETARG_C(getinstruction(fs, e), nresults + 1);
   }
   else if (e->k == VVARARG) {
-    SETARG_B(getcode(fs, e), nresults+1);
-    SETARG_A(getcode(fs, e), fs->freereg);
+    Instruction *pc = &getinstruction(fs, e);
+    SETARG_B(*pc, nresults + 1);
+    SETARG_A(*pc, fs->freereg);
     luaK_reserveregs(fs, 1);
   }
+  else lua_assert(nresults == LUA_MULTRET);
 }
 
 
+/*
+** Fix an expression to return one result.
+** If expression is not a multi-ret expression (function call or
+** vararg), it already returns one result, so nothing needs to be done.
+** Function calls become VNONRELOC expressions (as its result comes
+** fixed in the base register of the call), while vararg expressions
+** become VRELOCABLE (as OP_VARARG puts its results where it wants).
+** (Calls are created returning one result, so that does not need
+** to be fixed.)
+*/
 void luaK_setoneret (FuncState *fs, expdesc *e) {
   if (e->k == VCALL) {  /* expression is an open function call? */
-    e->k = VNONRELOC;
-    e->u.info = GETARG_A(getcode(fs, e));
+    /* already returns 1 value */
+    lua_assert(GETARG_C(getinstruction(fs, e)) == 2);
+    e->k = VNONRELOC;  /* result has fixed position */
+    e->u.info = GETARG_A(getinstruction(fs, e));
   }
   else if (e->k == VVARARG) {
-    SETARG_B(getcode(fs, e), 2);
+    SETARG_B(getinstruction(fs, e), 2);
     e->k = VRELOCABLE;  /* can relocate its simple result */
   }
 }
 
 
+/*
+** Ensure that expression 'e' is not a variable.
+*/
 void luaK_dischargevars (FuncState *fs, expdesc *e) {
   switch (e->k) {
-    case VLOCAL: {
-      e->k = VNONRELOC;
+    case VLOCAL: {  /* already in a register */
+      e->k = VNONRELOC;  /* becomes a non-relocatable value */
       break;
     }
-    case VUPVAL: {
+    case VUPVAL: {  /* move value to some (pending) register */
       e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0);
       e->k = VRELOCABLE;
       break;
     }
     case VINDEXED: {
-      OpCode op = OP_GETTABUP;  /* assume 't' is in an upvalue */
+      OpCode op;
       freereg(fs, e->u.ind.idx);
-      if (e->u.ind.vt == VLOCAL) {  /* 't' is in a register? */
+      if (e->u.ind.vt == VLOCAL) {  /* is 't' in a register? */
         freereg(fs, e->u.ind.t);
         op = OP_GETTABLE;
       }
+      else {
+        lua_assert(e->u.ind.vt == VUPVAL);
+        op = OP_GETTABUP;  /* 't' is in an upvalue */
+      }
       e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx);
       e->k = VRELOCABLE;
       break;
     }
-    case VVARARG:
-    case VCALL: {
+    case VVARARG: case VCALL: {
       luaK_setoneret(fs, e);
       break;
     }
@@ -436,12 +588,10 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) {
 }
 
 
-static int code_label (FuncState *fs, int A, int b, int jump) {
-  luaK_getlabel(fs);  /* those instructions may be jump targets */
-  return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
-}
-
-
+/*
+** Ensures expression value is in register 'reg' (and therefore
+** 'e' will become a non-relocatable expression).
+*/
 static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
   luaK_dischargevars(fs, e);
   switch (e->k) {
@@ -466,8 +616,8 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
       break;
     }
     case VRELOCABLE: {
-      Instruction *pc = &getcode(fs, e);
-      SETARG_A(*pc, reg);
+      Instruction *pc = &getinstruction(fs, e);
+      SETARG_A(*pc, reg);  /* instruction will put result in 'reg' */
       break;
     }
     case VNONRELOC: {
@@ -476,7 +626,7 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
       break;
     }
     default: {
-      lua_assert(e->k == VVOID || e->k == VJMP);
+      lua_assert(e->k == VJMP);
       return;  /* nothing to do... */
     }
   }
@@ -485,17 +635,46 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
 }
 
 
+/*
+** Ensures expression value is in any register.
+*/
 static void discharge2anyreg (FuncState *fs, expdesc *e) {
-  if (e->k != VNONRELOC) {
-    luaK_reserveregs(fs, 1);
-    discharge2reg(fs, e, fs->freereg-1);
+  if (e->k != VNONRELOC) {  /* no fixed register yet? */
+    luaK_reserveregs(fs, 1);  /* get a register */
+    discharge2reg(fs, e, fs->freereg-1);  /* put value there */
   }
 }
 
 
+static int code_loadbool (FuncState *fs, int A, int b, int jump) {
+  luaK_getlabel(fs);  /* those instructions may be jump targets */
+  return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
+}
+
+
+/*
+** check whether list has any jump that do not produce a value
+** or produce an inverted value
+*/
+static int need_value (FuncState *fs, int list) {
+  for (; list != NO_JUMP; list = getjump(fs, list)) {
+    Instruction i = *getjumpcontrol(fs, list);
+    if (GET_OPCODE(i) != OP_TESTSET) return 1;
+  }
+  return 0;  /* not found */
+}
+
+
+/*
+** Ensures final expression result (including results from its jump
+** lists) is in register 'reg'.
+** If expression has jumps, need to patch these jumps either to
+** its final position or to "load" instructions (for those tests
+** that do not produce values).
+*/
 static void exp2reg (FuncState *fs, expdesc *e, int reg) {
   discharge2reg(fs, e, reg);
-  if (e->k == VJMP)
+  if (e->k == VJMP)  /* expression itself is a test? */
     luaK_concat(fs, &e->t, e->u.info);  /* put this jump in 't' list */
   if (hasjumps(e)) {
     int final;  /* position after whole expression */
@@ -503,8 +682,8 @@ static void exp2reg (FuncState *fs, expdesc *e, int reg) {
     int p_t = NO_JUMP;  /* position of an eventual LOAD true */
     if (need_value(fs, e->t) || need_value(fs, e->f)) {
       int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
-      p_f = code_label(fs, reg, 0, 1);
-      p_t = code_label(fs, reg, 1, 0);
+      p_f = code_loadbool(fs, reg, 0, 1);
+      p_t = code_loadbool(fs, reg, 1, 0);
       luaK_patchtohere(fs, fj);
     }
     final = luaK_getlabel(fs);
@@ -517,6 +696,10 @@ static void exp2reg (FuncState *fs, expdesc *e, int reg) {
 }
 
 
+/*
+** Ensures final expression result (including results from its jump
+** lists) is in next available register.
+*/
 void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
   luaK_dischargevars(fs, e);
   freeexp(fs, e);
@@ -525,26 +708,39 @@ void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
 }
 
 
+/*
+** Ensures final expression result (including results from its jump
+** lists) is in some (any) register and return that register.
+*/
 int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
   luaK_dischargevars(fs, e);
-  if (e->k == VNONRELOC) {
-    if (!hasjumps(e)) return e->u.info;  /* exp is already in a register */
+  if (e->k == VNONRELOC) {  /* expression already has a register? */
+    if (!hasjumps(e))  /* no jumps? */
+      return e->u.info;  /* result is already in a register */
     if (e->u.info >= fs->nactvar) {  /* reg. is not a local? */
-      exp2reg(fs, e, e->u.info);  /* put value on it */
+      exp2reg(fs, e, e->u.info);  /* put final result in it */
       return e->u.info;
     }
   }
-  luaK_exp2nextreg(fs, e);  /* default */
+  luaK_exp2nextreg(fs, e);  /* otherwise, use next available register */
   return e->u.info;
 }
 
 
+/*
+** Ensures final expression result is either in a register or in an
+** upvalue.
+*/
 void luaK_exp2anyregup (FuncState *fs, expdesc *e) {
   if (e->k != VUPVAL || hasjumps(e))
     luaK_exp2anyreg(fs, e);
 }
 
 
+/*
+** Ensures final expression result is either in a register or it is
+** a constant.
+*/
 void luaK_exp2val (FuncState *fs, expdesc *e) {
   if (hasjumps(e))
     luaK_exp2anyreg(fs, e);
@@ -553,35 +749,26 @@ void luaK_exp2val (FuncState *fs, expdesc *e) {
 }
 
 
+/*
+** Ensures final expression result is in a valid R/K index
+** (that is, it is either in a register or in 'k' with an index
+** in the range of R/K indices).
+** Returns R/K index.
+*/
 int luaK_exp2RK (FuncState *fs, expdesc *e) {
   luaK_exp2val(fs, e);
-  switch (e->k) {
-    case VTRUE:
-    case VFALSE:
-    case VNIL: {
-      if (fs->nk <= MAXINDEXRK) {  /* constant fits in RK operand? */
-        e->u.info = (e->k == VNIL) ? nilK(fs) : boolK(fs, (e->k == VTRUE));
-        e->k = VK;
-        return RKASK(e->u.info);
-      }
-      else break;
-    }
-    case VKINT: {
-      e->u.info = luaK_intK(fs, e->u.ival);
-      e->k = VK;
-      goto vk;
-    }
-    case VKFLT: {
-      e->u.info = luaK_numberK(fs, e->u.nval);
-      e->k = VK;
-    }
-    /* FALLTHROUGH */
-    case VK: {
+  switch (e->k) {  /* move constants to 'k' */
+    case VTRUE: e->u.info = boolK(fs, 1); goto vk;
+    case VFALSE: e->u.info = boolK(fs, 0); goto vk;
+    case VNIL: e->u.info = nilK(fs); goto vk;
+    case VKINT: e->u.info = luaK_intK(fs, e->u.ival); goto vk;
+    case VKFLT: e->u.info = luaK_numberK(fs, e->u.nval); goto vk;
+    case VK:
      vk:
+      e->k = VK;
       if (e->u.info <= MAXINDEXRK)  /* constant fits in 'argC'? */
         return RKASK(e->u.info);
       else break;
-    }
     default: break;
   }
   /* not a constant in the right range: put it in a register */
@@ -589,11 +776,14 @@ int luaK_exp2RK (FuncState *fs, expdesc *e) {
 }
 
 
+/*
+** Generate code to store result of expression 'ex' into variable 'var'.
+*/
 void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
   switch (var->k) {
     case VLOCAL: {
       freeexp(fs, ex);
-      exp2reg(fs, ex, var->u.info);
+      exp2reg(fs, ex, var->u.info);  /* compute 'ex' into proper place */
       return;
     }
     case VUPVAL: {
@@ -607,29 +797,32 @@ void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
       luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e);
       break;
     }
-    default: {
-      lua_assert(0);  /* invalid var kind to store */
-      break;
-    }
+    default: lua_assert(0);  /* invalid var kind to store */
   }
   freeexp(fs, ex);
 }
 
 
+/*
+** Emit SELF instruction (convert expression 'e' into 'e:key(e,').
+*/
 void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
   int ereg;
   luaK_exp2anyreg(fs, e);
   ereg = e->u.info;  /* register where 'e' was placed */
   freeexp(fs, e);
   e->u.info = fs->freereg;  /* base register for op_self */
-  e->k = VNONRELOC;
+  e->k = VNONRELOC;  /* self expression has a fixed register */
   luaK_reserveregs(fs, 2);  /* function and 'self' produced by op_self */
   luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key));
   freeexp(fs, key);
 }
 
 
-static void invertjump (FuncState *fs, expdesc *e) {
+/*
+** Negate condition 'e' (where 'e' is a comparison).
+*/
+static void negatecondition (FuncState *fs, expdesc *e) {
   Instruction *pc = getjumpcontrol(fs, e->u.info);
   lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
                                            GET_OPCODE(*pc) != OP_TEST);
@@ -637,9 +830,15 @@ static void invertjump (FuncState *fs, expdesc *e) {
 }
 
 
+/*
+** Emit instruction to jump if 'e' is 'cond' (that is, if 'cond'
+** is true, code will jump if 'e' is true.) Return jump position.
+** Optimize when 'e' is 'not' something, inverting the condition
+** and removing the 'not'.
+*/
 static int jumponcond (FuncState *fs, expdesc *e, int cond) {
   if (e->k == VRELOCABLE) {
-    Instruction ie = getcode(fs, e);
+    Instruction ie = getinstruction(fs, e);
     if (GET_OPCODE(ie) == OP_NOT) {
       fs->pc--;  /* remove previous OP_NOT */
       return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);
@@ -652,13 +851,16 @@ static int jumponcond (FuncState *fs, expdesc *e, int cond) {
 }
 
 
+/*
+** Emit code to go through if 'e' is true, jump otherwise.
+*/
 void luaK_goiftrue (FuncState *fs, expdesc *e) {
-  int pc;  /* pc of last jump */
+  int pc;  /* pc of new jump */
   luaK_dischargevars(fs, e);
   switch (e->k) {
-    case VJMP: {
-      invertjump(fs, e);
-      pc = e->u.info;
+    case VJMP: {  /* condition? */
+      negatecondition(fs, e);  /* jump when it is false */
+      pc = e->u.info;  /* save jump position */
       break;
     }
     case VK: case VKFLT: case VKINT: case VTRUE: {
@@ -666,22 +868,25 @@ void luaK_goiftrue (FuncState *fs, expdesc *e) {
       break;
     }
     default: {
-      pc = jumponcond(fs, e, 0);
+      pc = jumponcond(fs, e, 0);  /* jump when false */
       break;
     }
   }
-  luaK_concat(fs, &e->f, pc);  /* insert last jump in 'f' list */
-  luaK_patchtohere(fs, e->t);
+  luaK_concat(fs, &e->f, pc);  /* insert new jump in false list */
+  luaK_patchtohere(fs, e->t);  /* true list jumps to here (to go through) */
   e->t = NO_JUMP;
 }
 
 
+/*
+** Emit code to go through if 'e' is false, jump otherwise.
+*/
 void luaK_goiffalse (FuncState *fs, expdesc *e) {
-  int pc;  /* pc of last jump */
+  int pc;  /* pc of new jump */
   luaK_dischargevars(fs, e);
   switch (e->k) {
     case VJMP: {
-      pc = e->u.info;
+      pc = e->u.info;  /* already jump if true */
       break;
     }
     case VNIL: case VFALSE: {
@@ -689,29 +894,32 @@ void luaK_goiffalse (FuncState *fs, expdesc *e) {
       break;
     }
     default: {
-      pc = jumponcond(fs, e, 1);
+      pc = jumponcond(fs, e, 1);  /* jump if true */
       break;
     }
   }
-  luaK_concat(fs, &e->t, pc);  /* insert last jump in 't' list */
-  luaK_patchtohere(fs, e->f);
+  luaK_concat(fs, &e->t, pc);  /* insert new jump in 't' list */
+  luaK_patchtohere(fs, e->f);  /* false list jumps to here (to go through) */
   e->f = NO_JUMP;
 }
 
 
+/*
+** Code 'not e', doing constant folding.
+*/
 static void codenot (FuncState *fs, expdesc *e) {
   luaK_dischargevars(fs, e);
   switch (e->k) {
     case VNIL: case VFALSE: {
-      e->k = VTRUE;
+      e->k = VTRUE;  /* true == not nil == not false */
       break;
     }
     case VK: case VKFLT: case VKINT: case VTRUE: {
-      e->k = VFALSE;
+      e->k = VFALSE;  /* false == not "x" == not 0.5 == not 1 == not true */
       break;
     }
     case VJMP: {
-      invertjump(fs, e);
+      negatecondition(fs, e);
       break;
     }
     case VRELOCABLE:
@@ -722,30 +930,32 @@ static void codenot (FuncState *fs, expdesc *e) {
       e->k = VRELOCABLE;
       break;
     }
-    default: {
-      lua_assert(0);  /* cannot happen */
-      break;
-    }
+    default: lua_assert(0);  /* cannot happen */
   }
   /* interchange true and false lists */
   { int temp = e->f; e->f = e->t; e->t = temp; }
-  removevalues(fs, e->f);
+  removevalues(fs, e->f);  /* values are useless when negated */
   removevalues(fs, e->t);
 }
 
 
+/*
+** Create expression 't[k]'. 't' must have its final result already in a
+** register or upvalue.
+*/
 void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
-  lua_assert(!hasjumps(t));
-  t->u.ind.t = t->u.info;
-  t->u.ind.idx = luaK_exp2RK(fs, k);
-  t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL
-                                 : check_exp(vkisinreg(t->k), VLOCAL);
+  lua_assert(!hasjumps(t) && (vkisinreg(t->k) || t->k == VUPVAL));
+  t->u.ind.t = t->u.info;  /* register or upvalue index */
+  t->u.ind.idx = luaK_exp2RK(fs, k);  /* R/K index for key */
+  t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL : VLOCAL;
   t->k = VINDEXED;
 }
 
 
 /*
-** return false if folding can raise an error
+** Return false if folding can raise an error.
+** Bitwise operations need operands convertible to integers; division
+** operations cannot have 0 as divisor.
 */
 static int validop (int op, TValue *v1, TValue *v2) {
   switch (op) {
@@ -762,9 +972,11 @@ static int validop (int op, TValue *v1, TValue *v2) {
 
 
 /*
-** Try to "constant-fold" an operation; return 1 iff successful
+** Try to "constant-fold" an operation; return 1 iff successful.
+** (In this case, 'e1' has the final result.)
 */
-static int constfolding (FuncState *fs, int op, expdesc *e1, expdesc *e2) {
+static int constfolding (FuncState *fs, int op, expdesc *e1,
+                                                const expdesc *e2) {
   TValue v1, v2, res;
   if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2))
     return 0;  /* non-numeric operands or not safe to fold */
@@ -773,7 +985,7 @@ static int constfolding (FuncState *fs, int op, expdesc *e1, expdesc *e2) {
     e1->k = VKINT;
     e1->u.ival = ivalue(&res);
   }
-  else {  /* folds neither NaN nor 0.0 (to avoid collapsing with -0.0) */
+  else {  /* folds neither NaN nor 0.0 (to avoid problems with -0.0) */
     lua_Number n = fltvalue(&res);
     if (luai_numisnan(n) || n == 0)
       return 0;
@@ -785,81 +997,100 @@ static int constfolding (FuncState *fs, int op, expdesc *e1, expdesc *e2) {
 
 
 /*
-** Code for binary and unary expressions that "produce values"
-** (arithmetic operations, bitwise operations, concat, length). First
-** try to do constant folding (only for numeric [arithmetic and
-** bitwise] operations, which is what 'lua_arith' accepts).
-** Expression to produce final result will be encoded in 'e1'.
+** Emit code for unary expressions that "produce values"
+** (everything but 'not').
+** Expression to produce final result will be encoded in 'e'.
 */
-static void codeexpval (FuncState *fs, OpCode op,
-                        expdesc *e1, expdesc *e2, int line) {
-  lua_assert(op >= OP_ADD);
-  if (op <= OP_BNOT && constfolding(fs, (op - OP_ADD) + LUA_OPADD, e1, e2))
-    return;  /* result has been folded */
-  else {
-    int o1, o2;
-    /* move operands to registers (if needed) */
-    if (op == OP_UNM || op == OP_BNOT || op == OP_LEN) {  /* unary op? */
-      o2 = 0;  /* no second expression */
-      o1 = luaK_exp2anyreg(fs, e1);  /* cannot operate on constants */
-    }
-    else {  /* regular case (binary operators) */
-      o2 = luaK_exp2RK(fs, e2);  /* both operands are "RK" */
-      o1 = luaK_exp2RK(fs, e1);
-    }
-    if (o1 > o2) {  /* free registers in proper order */
-      freeexp(fs, e1);
-      freeexp(fs, e2);
-    }
-    else {
-      freeexp(fs, e2);
-      freeexp(fs, e1);
-    }
-    e1->u.info = luaK_codeABC(fs, op, 0, o1, o2);  /* generate opcode */
-    e1->k = VRELOCABLE;  /* all those operations are relocable */
-    luaK_fixline(fs, line);
-  }
+static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) {
+  int r = luaK_exp2anyreg(fs, e);  /* opcodes operate only on registers */
+  freeexp(fs, e);
+  e->u.info = luaK_codeABC(fs, op, 0, r, 0);  /* generate opcode */
+  e->k = VRELOCABLE;  /* all those operations are relocatable */
+  luaK_fixline(fs, line);
 }
 
 
-static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1,
-                                                          expdesc *e2) {
-  int o1 = luaK_exp2RK(fs, e1);
-  int o2 = luaK_exp2RK(fs, e2);
-  freeexp(fs, e2);
-  freeexp(fs, e1);
-  if (cond == 0 && op != OP_EQ) {
-    int temp;  /* exchange args to replace by '<' or '<=' */
-    temp = o1; o1 = o2; o2 = temp;  /* o1 <==> o2 */
-    cond = 1;
+/*
+** Emit code for binary expressions that "produce values"
+** (everything but logical operators 'and'/'or' and comparison
+** operators).
+** Expression to produce final result will be encoded in 'e1'.
+** Because 'luaK_exp2RK' can free registers, its calls must be
+** in "stack order" (that is, first on 'e2', which may have more
+** recent registers to be released).
+*/
+static void codebinexpval (FuncState *fs, OpCode op,
+                           expdesc *e1, expdesc *e2, int line) {
+  int rk2 = luaK_exp2RK(fs, e2);  /* both operands are "RK" */
+  int rk1 = luaK_exp2RK(fs, e1);
+  freeexps(fs, e1, e2);
+  e1->u.info = luaK_codeABC(fs, op, 0, rk1, rk2);  /* generate opcode */
+  e1->k = VRELOCABLE;  /* all those operations are relocatable */
+  luaK_fixline(fs, line);
+}
+
+
+/*
+** Emit code for comparisons.
+** 'e1' was already put in R/K form by 'luaK_infix'.
+*/
+static void codecomp (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
+  int rk1 = (e1->k == VK) ? RKASK(e1->u.info)
+                          : check_exp(e1->k == VNONRELOC, e1->u.info);
+  int rk2 = luaK_exp2RK(fs, e2);
+  freeexps(fs, e1, e2);
+  switch (opr) {
+    case OPR_NE: {  /* '(a ~= b)' ==> 'not (a == b)' */
+      e1->u.info = condjump(fs, OP_EQ, 0, rk1, rk2);
+      break;
+    }
+    case OPR_GT: case OPR_GE: {
+      /* '(a > b)' ==> '(b < a)';  '(a >= b)' ==> '(b <= a)' */
+      OpCode op = cast(OpCode, (opr - OPR_NE) + OP_EQ);
+      e1->u.info = condjump(fs, op, 1, rk2, rk1);  /* invert operands */
+      break;
+    }
+    default: {  /* '==', '<', '<=' use their own opcodes */
+      OpCode op = cast(OpCode, (opr - OPR_EQ) + OP_EQ);
+      e1->u.info = condjump(fs, op, 1, rk1, rk2);
+      break;
+    }
   }
-  e1->u.info = condjump(fs, op, cond, o1, o2);
   e1->k = VJMP;
 }
 
 
+/*
+** Apply prefix operation 'op' to expression 'e'.
+*/
 void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) {
-  expdesc e2;
-  e2.t = e2.f = NO_JUMP; e2.k = VKINT; e2.u.ival = 0;
+  static const expdesc ef = {VKINT, {0}, NO_JUMP, NO_JUMP};
   switch (op) {
-    case OPR_MINUS: case OPR_BNOT: case OPR_LEN: {
-      codeexpval(fs, cast(OpCode, (op - OPR_MINUS) + OP_UNM), e, &e2, line);
+    case OPR_MINUS: case OPR_BNOT:  /* use 'ef' as fake 2nd operand */
+      if (constfolding(fs, op + LUA_OPUNM, e, &ef))
+        break;
+      /* FALLTHROUGH */
+    case OPR_LEN:
+      codeunexpval(fs, cast(OpCode, op + OP_UNM), e, line);
       break;
-    }
     case OPR_NOT: codenot(fs, e); break;
     default: lua_assert(0);
   }
 }
 
 
+/*
+** Process 1st operand 'v' of binary operation 'op' before reading
+** 2nd operand.
+*/
 void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
   switch (op) {
     case OPR_AND: {
-      luaK_goiftrue(fs, v);
+      luaK_goiftrue(fs, v);  /* go ahead only if 'v' is true */
       break;
     }
     case OPR_OR: {
-      luaK_goiffalse(fs, v);
+      luaK_goiffalse(fs, v);  /* go ahead only if 'v' is false */
       break;
     }
     case OPR_CONCAT: {
@@ -871,7 +1102,9 @@ void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
     case OPR_MOD: case OPR_POW:
     case OPR_BAND: case OPR_BOR: case OPR_BXOR:
     case OPR_SHL: case OPR_SHR: {
-      if (!tonumeral(v, NULL)) luaK_exp2RK(fs, v);
+      if (!tonumeral(v, NULL))
+        luaK_exp2RK(fs, v);
+      /* else keep numeral, which may be folded with 2nd operand */
       break;
     }
     default: {
@@ -882,18 +1115,24 @@ void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
 }
 
 
+/*
+** Finalize code for binary operation, after reading 2nd operand.
+** For '(a .. b .. c)' (which is '(a .. (b .. c))', because
+** concatenation is right associative), merge second CONCAT into first
+** one.
+*/
 void luaK_posfix (FuncState *fs, BinOpr op,
                   expdesc *e1, expdesc *e2, int line) {
   switch (op) {
     case OPR_AND: {
-      lua_assert(e1->t == NO_JUMP);  /* list must be closed */
+      lua_assert(e1->t == NO_JUMP);  /* list closed by 'luK_infix' */
       luaK_dischargevars(fs, e2);
       luaK_concat(fs, &e2->f, e1->f);
       *e1 = *e2;
       break;
     }
     case OPR_OR: {
-      lua_assert(e1->f == NO_JUMP);  /* list must be closed */
+      lua_assert(e1->f == NO_JUMP);  /* list closed by 'luK_infix' */
       luaK_dischargevars(fs, e2);
       luaK_concat(fs, &e2->t, e1->t);
       *e1 = *e2;
@@ -901,15 +1140,16 @@ void luaK_posfix (FuncState *fs, BinOpr op,
     }
     case OPR_CONCAT: {
       luaK_exp2val(fs, e2);
-      if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {
-        lua_assert(e1->u.info == GETARG_B(getcode(fs, e2))-1);
+      if (e2->k == VRELOCABLE &&
+          GET_OPCODE(getinstruction(fs, e2)) == OP_CONCAT) {
+        lua_assert(e1->u.info == GETARG_B(getinstruction(fs, e2))-1);
         freeexp(fs, e1);
-        SETARG_B(getcode(fs, e2), e1->u.info);
+        SETARG_B(getinstruction(fs, e2), e1->u.info);
         e1->k = VRELOCABLE; e1->u.info = e2->u.info;
       }
       else {
         luaK_exp2nextreg(fs, e2);  /* operand must be on the 'stack' */
-        codeexpval(fs, OP_CONCAT, e1, e2, line);
+        codebinexpval(fs, OP_CONCAT, e1, e2, line);
       }
       break;
     }
@@ -917,15 +1157,13 @@ void luaK_posfix (FuncState *fs, BinOpr op,
     case OPR_IDIV: case OPR_MOD: case OPR_POW:
     case OPR_BAND: case OPR_BOR: case OPR_BXOR:
     case OPR_SHL: case OPR_SHR: {
-      codeexpval(fs, cast(OpCode, (op - OPR_ADD) + OP_ADD), e1, e2, line);
-      break;
-    }
-    case OPR_EQ: case OPR_LT: case OPR_LE: {
-      codecomp(fs, cast(OpCode, (op - OPR_EQ) + OP_EQ), 1, e1, e2);
+      if (!constfolding(fs, op + LUA_OPADD, e1, e2))
+        codebinexpval(fs, cast(OpCode, op + OP_ADD), e1, e2, line);
       break;
     }
+    case OPR_EQ: case OPR_LT: case OPR_LE:
     case OPR_NE: case OPR_GT: case OPR_GE: {
-      codecomp(fs, cast(OpCode, (op - OPR_NE) + OP_EQ), 0, e1, e2);
+      codecomp(fs, op, e1, e2);
       break;
     }
     default: lua_assert(0);
@@ -933,15 +1171,25 @@ void luaK_posfix (FuncState *fs, BinOpr op,
 }
 
 
+/*
+** Change line information associated with current position.
+*/
 void luaK_fixline (FuncState *fs, int line) {
   fs->f->lineinfo[fs->pc - 1] = line;
 }
 
 
+/*
+** Emit a SETLIST instruction.
+** 'base' is register that keeps table;
+** 'nelems' is #table plus those to be stored now;
+** 'tostore' is number of values (in registers 'base + 1',...) to add to
+** table (or LUA_MULTRET to add up to stack top).
+*/
 void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {
   int c =  (nelems - 1)/LFIELDS_PER_FLUSH + 1;
   int b = (tostore == LUA_MULTRET) ? 0 : tostore;
-  lua_assert(tostore != 0);
+  lua_assert(tostore != 0 && tostore <= LFIELDS_PER_FLUSH);
   if (c <= MAXARG_C)
     luaK_codeABC(fs, OP_SETLIST, base, b, c);
   else if (c <= MAXARG_Ax) {
diff --git a/source/extern/lua/lcode.h b/source/extern/lua/lcode.h
index 43ab86d..882dc9c 100644
--- a/source/extern/lua/lcode.h
+++ b/source/extern/lua/lcode.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.h,v 1.63 2013/12/30 20:47:58 roberto Exp $
+** $Id: lcode.h,v 1.64.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -40,7 +40,8 @@ typedef enum BinOpr {
 typedef enum UnOpr { OPR_MINUS, OPR_BNOT, OPR_NOT, OPR_LEN, OPR_NOUNOPR } UnOpr;
 
 
-#define getcode(fs,e)	((fs)->f->code[(e)->u.info])
+/* get (pointer to) instruction of given 'expdesc' */
+#define getinstruction(fs,e)	((fs)->f->code[(e)->u.info])
 
 #define luaK_codeAsBx(fs,o,A,sBx)	luaK_codeABx(fs,o,A,(sBx)+MAXARG_sBx)
 
diff --git a/source/extern/lua/lcorolib.c b/source/extern/lua/lcorolib.c
index 0c0b7fa..0b17af9 100644
--- a/source/extern/lua/lcorolib.c
+++ b/source/extern/lua/lcorolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcorolib.c,v 1.9 2014/11/02 19:19:04 roberto Exp $
+** $Id: lcorolib.c,v 1.10.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Coroutine Library
 ** See Copyright Notice in lua.h
 */
@@ -75,7 +75,7 @@ static int luaB_auxwrap (lua_State *L) {
   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
   int r = auxresume(L, co, lua_gettop(L));
   if (r < 0) {
-    if (lua_isstring(L, -1)) {  /* error object is a string? */
+    if (lua_type(L, -1) == LUA_TSTRING) {  /* error object is a string? */
       luaL_where(L, 1);  /* add extra info */
       lua_insert(L, -2);
       lua_concat(L, 2);
diff --git a/source/extern/lua/lctype.c b/source/extern/lua/lctype.c
index ae9367e..f8ad7a2 100644
--- a/source/extern/lua/lctype.c
+++ b/source/extern/lua/lctype.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lctype.c,v 1.12 2014/11/02 19:19:04 roberto Exp $
+** $Id: lctype.c,v 1.12.1.1 2017/04/19 17:20:42 roberto Exp $
 ** 'ctype' functions for Lua
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/lctype.h b/source/extern/lua/lctype.h
index 99c7d12..b09b21a 100644
--- a/source/extern/lua/lctype.h
+++ b/source/extern/lua/lctype.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lctype.h,v 1.12 2011/07/15 12:50:29 roberto Exp $
+** $Id: lctype.h,v 1.12.1.1 2013/04/12 18:48:47 roberto Exp $
 ** 'ctype' functions for Lua
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/ldblib.c b/source/extern/lua/ldblib.c
index 9151458..9d29afb 100644
--- a/source/extern/lua/ldblib.c
+++ b/source/extern/lua/ldblib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldblib.c,v 1.149 2015/02/19 17:06:21 roberto Exp $
+** $Id: ldblib.c,v 1.151.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Interface from Lua to its debug API
 ** See Copyright Notice in lua.h
 */
@@ -28,8 +28,8 @@ static const int HOOKKEY = 0;
 
 
 /*
-** If L1 != L, L1 can be in any state, and therefore there is no
-** garanties about its stack space; any push in L1 must be
+** If L1 != L, L1 can be in any state, and therefore there are no
+** guarantees about its stack space; any push in L1 must be
 ** checked.
 */
 static void checkstack (lua_State *L, lua_State *L1, int n) {
diff --git a/source/extern/lua/ldebug.c b/source/extern/lua/ldebug.c
index f76582c..bb0e1d4 100644
--- a/source/extern/lua/ldebug.c
+++ b/source/extern/lua/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.115 2015/05/22 17:45:56 roberto Exp $
+** $Id: ldebug.c,v 2.121.1.2 2017/07/10 17:21:50 roberto Exp $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -38,7 +38,8 @@
 #define ci_func(ci)		(clLvalue((ci)->func))
 
 
-static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);
+static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
+                                    const char **name);
 
 
 static int currentpc (CallInfo *ci) {
@@ -69,7 +70,13 @@ static void swapextra (lua_State *L) {
 
 
 /*
-** this function can be called asynchronous (e.g. during a signal)
+** This function can be called asynchronously (e.g. during a signal).
+** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by
+** 'resethookcount') are for debug only, and it is no problem if they
+** get arbitrary values (causes at most one wrong hook call). 'hookmask'
+** is an atomic value. We assume that pointers are atomic too (e.g., gcc
+** ensures that for all platforms where it runs). Moreover, 'hook' is
+** always checked before being called (see 'luaD_hook').
 */
 LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
   if (func == NULL || mask == 0) {  /* turn off hooks? */
@@ -126,10 +133,11 @@ static const char *upvalname (Proto *p, int uv) {
 
 static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
   int nparams = clLvalue(ci->func)->p->numparams;
-  if (n >= cast_int(ci->u.l.base - ci->func) - nparams)
+  int nvararg = cast_int(ci->u.l.base - ci->func) - nparams;
+  if (n <= -nvararg)
     return NULL;  /* no such vararg */
   else {
-    *pos = ci->func + nparams + n;
+    *pos = ci->func + nparams - n;
     return "(*vararg)";  /* generic name for any vararg */
   }
 }
@@ -141,7 +149,7 @@ static const char *findlocal (lua_State *L, CallInfo *ci, int n,
   StkId base;
   if (isLua(ci)) {
     if (n < 0)  /* access to vararg values? */
-      return findvararg(ci, -n, pos);
+      return findvararg(ci, n, pos);
     else {
       base = ci->u.l.base;
       name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
@@ -238,6 +246,20 @@ static void collectvalidlines (lua_State *L, Closure *f) {
 }
 
 
+static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
+  if (ci == NULL)  /* no 'ci'? */
+    return NULL;  /* no info */
+  else if (ci->callstatus & CIST_FIN) {  /* is this a finalizer? */
+    *name = "__gc";
+    return "metamethod";  /* report it as such */
+  }
+  /* calling function is a known Lua function? */
+  else if (!(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
+    return funcnamefromcode(L, ci->previous, name);
+  else return NULL;  /* no way to find a name */
+}
+
+
 static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
                        Closure *f, CallInfo *ci) {
   int status = 1;
@@ -268,11 +290,7 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
         break;
       }
       case 'n': {
-        /* calling function is a known Lua function? */
-        if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
-          ar->namewhat = getfuncname(L, ci->previous, &ar->name);
-        else
-          ar->namewhat = NULL;
+        ar->namewhat = getfuncname(L, ci, &ar->name);
         if (ar->namewhat == NULL) {
           ar->namewhat = "";  /* not found */
           ar->name = NULL;
@@ -465,8 +483,15 @@ static const char *getobjname (Proto *p, int lastpc, int reg,
 }
 
 
-static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
-  TMS tm = (TMS)0;  /* to avoid warnings */
+/*
+** Try to find a name for a function based on the code that called it.
+** (Only works when function was called by a Lua function.)
+** Returns what the name is (e.g., "for iterator", "method",
+** "metamethod") and sets '*name' to point to the name.
+*/
+static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
+                                     const char **name) {
+  TMS tm = (TMS)0;  /* (initial value avoids warnings) */
   Proto *p = ci_func(ci)->p;  /* calling function */
   int pc = currentpc(ci);  /* calling instruction index */
   Instruction i = p->code[pc];  /* calling instruction */
@@ -476,13 +501,13 @@ static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
   }
   switch (GET_OPCODE(i)) {
     case OP_CALL:
-    case OP_TAILCALL:  /* get function name */
-      return getobjname(p, pc, GETARG_A(i), name);
+    case OP_TAILCALL:
+      return getobjname(p, pc, GETARG_A(i), name);  /* get function name */
     case OP_TFORCALL: {  /* for iterator */
       *name = "for iterator";
        return "for iterator";
     }
-    /* all other instructions can call only through metamethods */
+    /* other instructions can do calls through metamethods */
     case OP_SELF: case OP_GETTABUP: case OP_GETTABLE:
       tm = TM_INDEX;
       break;
@@ -503,7 +528,8 @@ static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
     case OP_EQ: tm = TM_EQ; break;
     case OP_LT: tm = TM_LT; break;
     case OP_LE: tm = TM_LE; break;
-    default: lua_assert(0);  /* other instructions cannot call a function */
+    default:
+      return NULL;  /* cannot find a reasonable name */
   }
   *name = getstr(G(L)->tmname[tm]);
   return "metamethod";
@@ -558,7 +584,7 @@ static const char *varinfo (lua_State *L, const TValue *o) {
 
 
 l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
-  const char *t = objtypename(o);
+  const char *t = luaT_objtypename(L, o);
   luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o));
 }
 
@@ -590,9 +616,9 @@ l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
 
 
 l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
-  const char *t1 = objtypename(p1);
-  const char *t2 = objtypename(p2);
-  if (t1 == t2)
+  const char *t1 = luaT_objtypename(L, p1);
+  const char *t2 = luaT_objtypename(L, p2);
+  if (strcmp(t1, t2) == 0)
     luaG_runerror(L, "attempt to compare two %s values", t1);
   else
     luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
@@ -618,7 +644,7 @@ l_noret luaG_errormsg (lua_State *L) {
     setobjs2s(L, L->top, L->top - 1);  /* move argument */
     setobjs2s(L, L->top - 1, errfunc);  /* push function */
     L->top++;  /* assume EXTRA_STACK */
-    luaD_call(L, L->top - 2, 1, 0);  /* call it */
+    luaD_callnoyield(L, L->top - 2, 1);  /* call it */
   }
   luaD_throw(L, LUA_ERRRUN);
 }
@@ -628,6 +654,7 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
   CallInfo *ci = L->ci;
   const char *msg;
   va_list argp;
+  luaC_checkGC(L);  /* error message uses memory */
   va_start(argp, fmt);
   msg = luaO_pushvfstring(L, fmt, argp);  /* format message */
   va_end(argp);
@@ -640,9 +667,11 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
 void luaG_traceexec (lua_State *L) {
   CallInfo *ci = L->ci;
   lu_byte mask = L->hookmask;
-  int counthook = ((mask & LUA_MASKCOUNT) && L->hookcount == 0);
+  int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
   if (counthook)
     resethookcount(L);  /* reset count */
+  else if (!(mask & LUA_MASKLINE))
+    return;  /* no line hook and count != 0; nothing to be done */
   if (ci->callstatus & CIST_HOOKYIELD) {  /* called hook last time? */
     ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
     return;  /* do not call hook again (VM yielded, so it did not move) */
diff --git a/source/extern/lua/ldebug.h b/source/extern/lua/ldebug.h
index 0e31546..8cea0ee 100644
--- a/source/extern/lua/ldebug.h
+++ b/source/extern/lua/ldebug.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.h,v 2.14 2015/05/22 17:45:56 roberto Exp $
+** $Id: ldebug.h,v 2.14.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Auxiliary functions from Debug Interface module
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/ldo.c b/source/extern/lua/ldo.c
index 5c93a25..316e45c 100644
--- a/source/extern/lua/ldo.c
+++ b/source/extern/lua/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 2.138 2015/05/22 17:48:19 roberto Exp $
+** $Id: ldo.c,v 2.157.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -150,6 +150,11 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
 /* }====================================================== */
 
 
+/*
+** {==================================================================
+** Stack reallocation
+** ===================================================================
+*/
 static void correctstack (lua_State *L, TValue *oldstack) {
   CallInfo *ci;
   UpVal *up;
@@ -206,9 +211,9 @@ static int stackinuse (lua_State *L) {
   CallInfo *ci;
   StkId lim = L->top;
   for (ci = L->ci; ci != NULL; ci = ci->previous) {
-    lua_assert(ci->top <= L->stack_last);
     if (lim < ci->top) lim = ci->top;
   }
+  lua_assert(lim <= L->stack_last);
   return cast_int(lim - L->stack) + 1;  /* part of stack in use */
 }
 
@@ -216,22 +221,38 @@ static int stackinuse (lua_State *L) {
 void luaD_shrinkstack (lua_State *L) {
   int inuse = stackinuse(L);
   int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
-  if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK;
-  if (L->stacksize > LUAI_MAXSTACK)  /* was handling stack overflow? */
+  if (goodsize > LUAI_MAXSTACK)
+    goodsize = LUAI_MAXSTACK;  /* respect stack limit */
+  if (L->stacksize > LUAI_MAXSTACK)  /* had been handling stack overflow? */
     luaE_freeCI(L);  /* free all CIs (list grew because of an error) */
   else
     luaE_shrinkCI(L);  /* shrink list */
-  if (inuse > LUAI_MAXSTACK ||  /* still handling stack overflow? */
-      goodsize >= L->stacksize)  /* would grow instead of shrink? */
-    condmovestack(L);  /* don't change stack (change only for debugging) */
-  else
-    luaD_reallocstack(L, goodsize);  /* shrink it */
+  /* if thread is currently not handling a stack overflow and its
+     good size is smaller than current size, shrink its stack */
+  if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) &&
+      goodsize < L->stacksize)
+    luaD_reallocstack(L, goodsize);
+  else  /* don't change stack */
+    condmovestack(L,{},{});  /* (change only for debugging) */
 }
 
 
+void luaD_inctop (lua_State *L) {
+  luaD_checkstack(L, 1);
+  L->top++;
+}
+
+/* }================================================================== */
+
+
+/*
+** Call a hook for the given event. Make sure there is a hook to be
+** called. (Both 'L->hook' and 'L->hookmask', which triggers this
+** function, can be changed asynchronously by signals.)
+*/
 void luaD_hook (lua_State *L, int event, int line) {
   lua_Hook hook = L->hook;
-  if (hook && L->allowhook) {
+  if (hook && L->allowhook) {  /* make sure there is a hook */
     CallInfo *ci = L->ci;
     ptrdiff_t top = savestack(L, L->top);
     ptrdiff_t ci_top = savestack(L, ci->top);
@@ -273,15 +294,15 @@ static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
   int i;
   int nfixargs = p->numparams;
   StkId base, fixed;
-  lua_assert(actual >= nfixargs);
   /* move fixed parameters to final position */
-  luaD_checkstack(L, p->maxstacksize);  /* check again for new 'base' */
   fixed = L->top - actual;  /* first fixed argument */
   base = L->top;  /* final position of first argument */
-  for (i=0; i<nfixargs; i++) {
+  for (i = 0; i < nfixargs && i < actual; i++) {
     setobjs2s(L, L->top++, fixed + i);
-    setnilvalue(fixed + i);
+    setnilvalue(fixed + i);  /* erase original copy (for GC) */
   }
+  for (; i < nfixargs; i++)
+    setnilvalue(L->top++);  /* complete missing arguments */
   return base;
 }
 
@@ -304,85 +325,57 @@ static void tryfuncTM (lua_State *L, StkId func) {
 }
 
 
-
-#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
-
-
 /*
-** returns true if function has been executed (C function)
+** Given 'nres' results at 'firstResult', move 'wanted' of them to 'res'.
+** Handle most typical cases (zero results for commands, one result for
+** expressions, multiple results for tail calls/single parameters)
+** separated.
 */
-int luaD_precall (lua_State *L, StkId func, int nresults) {
-  lua_CFunction f;
-  CallInfo *ci;
-  int n;  /* number of arguments (Lua) or returns (C) */
-  ptrdiff_t funcr = savestack(L, func);
-  switch (ttype(func)) {
-    case LUA_TLCF:  /* light C function */
-      f = fvalue(func);
-      goto Cfunc;
-    case LUA_TCCL: {  /* C closure */
-      f = clCvalue(func)->f;
-     Cfunc:
-      luaC_checkGC(L);  /* stack grow uses memory */
-      luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
-      ci = next_ci(L);  /* now 'enter' new function */
-      ci->nresults = nresults;
-      ci->func = restorestack(L, funcr);
-      ci->top = L->top + LUA_MINSTACK;
-      lua_assert(ci->top <= L->stack_last);
-      ci->callstatus = 0;
-      if (L->hookmask & LUA_MASKCALL)
-        luaD_hook(L, LUA_HOOKCALL, -1);
-      lua_unlock(L);
-      n = (*f)(L);  /* do the actual call */
-      lua_lock(L);
-      api_checknelems(L, n);
-      luaD_poscall(L, L->top - n, n);
-      return 1;
+static int moveresults (lua_State *L, const TValue *firstResult, StkId res,
+                                      int nres, int wanted) {
+  switch (wanted) {  /* handle typical cases separately */
+    case 0: break;  /* nothing to move */
+    case 1: {  /* one result needed */
+      if (nres == 0)   /* no results? */
+        firstResult = luaO_nilobject;  /* adjust with nil */
+      setobjs2s(L, res, firstResult);  /* move it to proper place */
+      break;
     }
-    case LUA_TLCL: {  /* Lua function: prepare its call */
-      StkId base;
-      Proto *p = clLvalue(func)->p;
-      n = cast_int(L->top - func) - 1;  /* number of real arguments */
-      luaC_checkGC(L);  /* stack grow uses memory */
-      luaD_checkstack(L, p->maxstacksize);
-      for (; n < p->numparams; n++)
-        setnilvalue(L->top++);  /* complete missing arguments */
-      if (!p->is_vararg) {
-        func = restorestack(L, funcr);
-        base = func + 1;
-      }
-      else {
-        base = adjust_varargs(L, p, n);
-        func = restorestack(L, funcr);  /* previous call can change stack */
-      }
-      ci = next_ci(L);  /* now 'enter' new function */
-      ci->nresults = nresults;
-      ci->func = func;
-      ci->u.l.base = base;
-      ci->top = base + p->maxstacksize;
-      lua_assert(ci->top <= L->stack_last);
-      ci->u.l.savedpc = p->code;  /* starting point */
-      ci->callstatus = CIST_LUA;
-      L->top = ci->top;
-      if (L->hookmask & LUA_MASKCALL)
-        callhook(L, ci);
-      return 0;
+    case LUA_MULTRET: {
+      int i;
+      for (i = 0; i < nres; i++)  /* move all results to correct place */
+        setobjs2s(L, res + i, firstResult + i);
+      L->top = res + nres;
+      return 0;  /* wanted == LUA_MULTRET */
     }
-    default: {  /* not a function */
-      luaD_checkstack(L, 1);  /* ensure space for metamethod */
-      func = restorestack(L, funcr);  /* previous call may change stack */
-      tryfuncTM(L, func);  /* try to get '__call' metamethod */
-      return luaD_precall(L, func, nresults);  /* now it must be a function */
+    default: {
+      int i;
+      if (wanted <= nres) {  /* enough results? */
+        for (i = 0; i < wanted; i++)  /* move wanted results to correct place */
+          setobjs2s(L, res + i, firstResult + i);
+      }
+      else {  /* not enough results; use all of them plus nils */
+        for (i = 0; i < nres; i++)  /* move all results to correct place */
+          setobjs2s(L, res + i, firstResult + i);
+        for (; i < wanted; i++)  /* complete wanted number of results */
+          setnilvalue(res + i);
+      }
+      break;
     }
   }
+  L->top = res + wanted;  /* top points after the last result */
+  return 1;
 }
 
 
-int luaD_poscall (lua_State *L, StkId firstResult, int nres) {
+/*
+** Finishes a function call: calls hook if necessary, removes CallInfo,
+** moves current number of results to proper place; returns 0 iff call
+** wanted multiple (variable number of) results.
+*/
+int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
   StkId res;
-  int wanted, i;
-  CallInfo *ci = L->ci;
+  int wanted = ci->nresults;
   if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
     if (L->hookmask & LUA_MASKRET) {
       ptrdiff_t fr = savestack(L, firstResult);  /* hook may change stack */
@@ -392,15 +385,104 @@ int luaD_poscall (lua_State *L, StkId firstResult, int nres) {
     L->oldpc = ci->previous->u.l.savedpc;  /* 'oldpc' for caller function */
   }
   res = ci->func;  /* res == final position of 1st result */
-  wanted = ci->nresults;
   L->ci = ci->previous;  /* back to caller */
-  /* move results to correct place */
-  for (i = wanted; i != 0 && nres-- > 0; i--)
-    setobjs2s(L, res++, firstResult++);
-  while (i-- > 0)
-    setnilvalue(res++);
-  L->top = res;
-  return (wanted - LUA_MULTRET);  /* 0 iff wanted == LUA_MULTRET */
+  /* move results to proper place */
+  return moveresults(L, firstResult, res, nres, wanted);
+}
+
+
+
+#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
+
+
+/* macro to check stack size, preserving 'p' */
+#define checkstackp(L,n,p)  \
+  luaD_checkstackaux(L, n, \
+    ptrdiff_t t__ = savestack(L, p);  /* save 'p' */ \
+    luaC_checkGC(L),  /* stack grow uses memory */ \
+    p = restorestack(L, t__))  /* 'pos' part: restore 'p' */
+
+
+/*
+** Prepares a function call: checks the stack, creates a new CallInfo
+** entry, fills in the relevant information, calls hook if needed.
+** If function is a C function, does the call, too. (Otherwise, leave
+** the execution ('luaV_execute') to the caller, to allow stackless
+** calls.) Returns true iff function has been executed (C function).
+*/
+int luaD_precall (lua_State *L, StkId func, int nresults) {
+  lua_CFunction f;
+  CallInfo *ci;
+  switch (ttype(func)) {
+    case LUA_TCCL:  /* C closure */
+      f = clCvalue(func)->f;
+      goto Cfunc;
+    case LUA_TLCF:  /* light C function */
+      f = fvalue(func);
+     Cfunc: {
+      int n;  /* number of returns */
+      checkstackp(L, LUA_MINSTACK, func);  /* ensure minimum stack size */
+      ci = next_ci(L);  /* now 'enter' new function */
+      ci->nresults = nresults;
+      ci->func = func;
+      ci->top = L->top + LUA_MINSTACK;
+      lua_assert(ci->top <= L->stack_last);
+      ci->callstatus = 0;
+      if (L->hookmask & LUA_MASKCALL)
+        luaD_hook(L, LUA_HOOKCALL, -1);
+      lua_unlock(L);
+      n = (*f)(L);  /* do the actual call */
+      lua_lock(L);
+      api_checknelems(L, n);
+      luaD_poscall(L, ci, L->top - n, n);
+      return 1;
+    }
+    case LUA_TLCL: {  /* Lua function: prepare its call */
+      StkId base;
+      Proto *p = clLvalue(func)->p;
+      int n = cast_int(L->top - func) - 1;  /* number of real arguments */
+      int fsize = p->maxstacksize;  /* frame size */
+      checkstackp(L, fsize, func);
+      if (p->is_vararg)
+        base = adjust_varargs(L, p, n);
+      else {  /* non vararg function */
+        for (; n < p->numparams; n++)
+          setnilvalue(L->top++);  /* complete missing arguments */
+        base = func + 1;
+      }
+      ci = next_ci(L);  /* now 'enter' new function */
+      ci->nresults = nresults;
+      ci->func = func;
+      ci->u.l.base = base;
+      L->top = ci->top = base + fsize;
+      lua_assert(ci->top <= L->stack_last);
+      ci->u.l.savedpc = p->code;  /* starting point */
+      ci->callstatus = CIST_LUA;
+      if (L->hookmask & LUA_MASKCALL)
+        callhook(L, ci);
+      return 0;
+    }
+    default: {  /* not a function */
+      checkstackp(L, 1, func);  /* ensure space for metamethod */
+      tryfuncTM(L, func);  /* try to get '__call' metamethod */
+      return luaD_precall(L, func, nresults);  /* now it must be a function */
+    }
+  }
+}
+
+
+/*
+** Check appropriate error for stack overflow ("regular" overflow or
+** overflow while handling stack overflow). If 'nCalls' is larger than
+** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but
+** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to
+** allow overflow handling to work)
+*/
+static void stackerror (lua_State *L) {
+  if (L->nCcalls == LUAI_MAXCCALLS)
+    luaG_runerror(L, "C stack overflow");
+  else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3)))
+    luaD_throw(L, LUA_ERRERR);  /* error while handing stack error */
 }
 
 
@@ -410,21 +492,25 @@ int luaD_poscall (lua_State *L, StkId firstResult, int nres) {
 ** When returns, all the results are on the stack, starting at the original
 ** function position.
 */
-void luaD_call (lua_State *L, StkId func, int nResults, int allowyield) {
-  if (++L->nCcalls >= LUAI_MAXCCALLS) {
-    if (L->nCcalls == LUAI_MAXCCALLS)
-      luaG_runerror(L, "C stack overflow");
-    else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3)))
-      luaD_throw(L, LUA_ERRERR);  /* error while handing stack error */
-  }
-  if (!allowyield) L->nny++;
+void luaD_call (lua_State *L, StkId func, int nResults) {
+  if (++L->nCcalls >= LUAI_MAXCCALLS)
+    stackerror(L);
   if (!luaD_precall(L, func, nResults))  /* is a Lua function? */
     luaV_execute(L);  /* call it */
-  if (!allowyield) L->nny--;
   L->nCcalls--;
 }
 
 
+/*
+** Similar to 'luaD_call', but does not allow yields during the call
+*/
+void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
+  L->nny++;
+  luaD_call(L, func, nResults);
+  L->nny--;
+}
+
+
 /*
 ** Completes the execution of an interrupted C function, calling its
 ** continuation function.
@@ -437,19 +523,17 @@ static void finishCcall (lua_State *L, int status) {
   /* error status can only happen in a protected call */
   lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD);
   if (ci->callstatus & CIST_YPCALL) {  /* was inside a pcall? */
-    ci->callstatus &= ~CIST_YPCALL;  /* finish 'lua_pcall' */
-    L->errfunc = ci->u.c.old_errfunc;
+    ci->callstatus &= ~CIST_YPCALL;  /* continuation is also inside it */
+    L->errfunc = ci->u.c.old_errfunc;  /* with the same error function */
   }
   /* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already
      handled */
   adjustresults(L, ci->nresults);
-  /* call continuation function */
   lua_unlock(L);
-  n = (*ci->u.c.k)(L, status, ci->u.c.ctx);
+  n = (*ci->u.c.k)(L, status, ci->u.c.ctx);  /* call continuation function */
   lua_lock(L);
   api_checknelems(L, n);
-  /* finish 'luaD_precall' */
-  luaD_poscall(L, L->top - n, n);
+  luaD_poscall(L, ci, L->top - n, n);  /* finish 'luaD_precall' */
 }
 
 
@@ -512,15 +596,16 @@ static int recover (lua_State *L, int status) {
 
 
 /*
-** signal an error in the call to 'resume', not in the execution of the
-** coroutine itself. (Such errors should not be handled by any coroutine
-** error handler and should not kill the coroutine.)
+** Signal an error in the call to 'lua_resume', not in the execution
+** of the coroutine itself. (Such errors should not be handled by any
+** coroutine error handler and should not kill the coroutine.)
 */
-static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) {
-  L->top = firstArg;  /* remove args from the stack */
+static int resume_error (lua_State *L, const char *msg, int narg) {
+  L->top -= narg;  /* remove args from the stack */
   setsvalue2s(L, L->top, luaS_new(L, msg));  /* push error message */
   api_incr_top(L);
-  luaD_throw(L, -1);  /* jump back to 'lua_resume' */
+  lua_unlock(L);
+  return LUA_ERRRUN;
 }
 
 
@@ -532,22 +617,15 @@ static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) {
 ** coroutine.
 */
 static void resume (lua_State *L, void *ud) {
-  int nCcalls = L->nCcalls;
   int n = *(cast(int*, ud));  /* number of arguments */
   StkId firstArg = L->top - n;  /* first argument */
   CallInfo *ci = L->ci;
-  if (nCcalls >= LUAI_MAXCCALLS)
-    resume_error(L, "C stack overflow", firstArg);
-  if (L->status == LUA_OK) {  /* may be starting a coroutine */
-    if (ci != &L->base_ci)  /* not in base level? */
-      resume_error(L, "cannot resume non-suspended coroutine", firstArg);
-    /* coroutine is in base level; start running it */
+  if (L->status == LUA_OK) {  /* starting a coroutine? */
     if (!luaD_precall(L, firstArg - 1, LUA_MULTRET))  /* Lua function? */
       luaV_execute(L);  /* call it */
   }
-  else if (L->status != LUA_YIELD)
-    resume_error(L, "cannot resume dead coroutine", firstArg);
   else {  /* resuming from previous yield */
+    lua_assert(L->status == LUA_YIELD);
     L->status = LUA_OK;  /* mark that it is running (again) */
     ci->func = restorestack(L, ci->extra);
     if (isLua(ci))  /* yielded inside a hook? */
@@ -560,20 +638,27 @@ static void resume (lua_State *L, void *ud) {
         api_checknelems(L, n);
         firstArg = L->top - n;  /* yield results come from continuation */
       }
-      luaD_poscall(L, firstArg, n);  /* finish 'luaD_precall' */
+      luaD_poscall(L, ci, firstArg, n);  /* finish 'luaD_precall' */
     }
     unroll(L, NULL);  /* run continuation */
   }
-  lua_assert(nCcalls == L->nCcalls);
 }
 
 
 LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
   int status;
-  int oldnny = L->nny;  /* save "number of non-yieldable" calls */
+  unsigned short oldnny = L->nny;  /* save "number of non-yieldable" calls */
   lua_lock(L);
-  luai_userstateresume(L, nargs);
+  if (L->status == LUA_OK) {  /* may be starting a coroutine */
+    if (L->ci != &L->base_ci)  /* not in base level? */
+      return resume_error(L, "cannot resume non-suspended coroutine", nargs);
+  }
+  else if (L->status != LUA_YIELD)
+    return resume_error(L, "cannot resume dead coroutine", nargs);
   L->nCcalls = (from) ? from->nCcalls + 1 : 1;
+  if (L->nCcalls >= LUAI_MAXCCALLS)
+    return resume_error(L, "C stack overflow", nargs);
+  luai_userstateresume(L, nargs);
   L->nny = 0;  /* allow yields */
   api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
   status = luaD_rawrunprotected(L, resume, &nargs);
@@ -684,7 +769,7 @@ static void f_parser (lua_State *L, void *ud) {
   int c = zgetc(p->z);  /* read first character */
   if (c == LUA_SIGNATURE[0]) {
     checkmode(L, p->mode, "binary");
-    cl = luaU_undump(L, p->z, &p->buff, p->name);
+    cl = luaU_undump(L, p->z, p->name);
   }
   else {
     checkmode(L, p->mode, "text");
diff --git a/source/extern/lua/ldo.h b/source/extern/lua/ldo.h
index edade65..3b2983a 100644
--- a/source/extern/lua/ldo.h
+++ b/source/extern/lua/ldo.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.h,v 2.22 2015/05/22 17:48:19 roberto Exp $
+** $Id: ldo.h,v 2.29.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -13,11 +13,21 @@
 #include "lzio.h"
 
 
-#define luaD_checkstack(L,n)	if (L->stack_last - L->top <= (n)) \
-				    luaD_growstack(L, n); else condmovestack(L);
+/*
+** Macro to check stack size and grow stack if needed.  Parameters
+** 'pre'/'pos' allow the macro to preserve a pointer into the
+** stack across reallocations, doing the work only when needed.
+** 'condmovestack' is used in heavy tests to force a stack reallocation
+** at every check.
+*/
+#define luaD_checkstackaux(L,n,pre,pos)  \
+	if (L->stack_last - L->top <= (n)) \
+	  { pre; luaD_growstack(L, n); pos; } else { condmovestack(L,pre,pos); }
+
+/* In general, 'pre'/'pos' are empty (nothing to save) */
+#define luaD_checkstack(L,n)	luaD_checkstackaux(L,n,(void)0,(void)0)
 
 
-#define incr_top(L) {L->top++; luaD_checkstack(L,0);}
 
 #define savestack(L,p)		((char *)(p) - (char *)L->stack)
 #define restorestack(L,n)	((TValue *)((char *)L->stack + (n)))
@@ -30,14 +40,16 @@ LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
                                                   const char *mode);
 LUAI_FUNC void luaD_hook (lua_State *L, int event, int line);
 LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults);
-LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults,
-                                        int allowyield);
+LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
+LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
 LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u,
                                         ptrdiff_t oldtop, ptrdiff_t ef);
-LUAI_FUNC int luaD_poscall (lua_State *L, StkId firstResult, int nres);
+LUAI_FUNC int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult,
+                                          int nres);
 LUAI_FUNC void luaD_reallocstack (lua_State *L, int newsize);
 LUAI_FUNC void luaD_growstack (lua_State *L, int n);
 LUAI_FUNC void luaD_shrinkstack (lua_State *L);
+LUAI_FUNC void luaD_inctop (lua_State *L);
 
 LUAI_FUNC l_noret luaD_throw (lua_State *L, int errcode);
 LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud);
diff --git a/source/extern/lua/ldump.c b/source/extern/lua/ldump.c
index 4c04812..f025aca 100644
--- a/source/extern/lua/ldump.c
+++ b/source/extern/lua/ldump.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldump.c,v 2.36 2015/03/30 15:43:51 roberto Exp $
+** $Id: ldump.c,v 2.37.1.1 2017/04/19 17:20:42 roberto Exp $
 ** save precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -38,7 +38,7 @@ typedef struct {
 
 
 static void DumpBlock (const void *b, size_t size, DumpState *D) {
-  if (D->status == 0) {
+  if (D->status == 0 && size > 0) {
     lua_unlock(D->L);
     D->status = (*D->writer)(D->L, b, size, D->data);
     lua_lock(D->L);
diff --git a/source/extern/lua/lfunc.c b/source/extern/lua/lfunc.c
index 67967da..ccafbb8 100644
--- a/source/extern/lua/lfunc.c
+++ b/source/extern/lua/lfunc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.c,v 2.45 2014/11/02 19:19:04 roberto Exp $
+** $Id: lfunc.c,v 2.45.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/lfunc.h b/source/extern/lua/lfunc.h
index 2eeb0d5..c916e98 100644
--- a/source/extern/lua/lfunc.h
+++ b/source/extern/lua/lfunc.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lfunc.h,v 2.15 2015/01/13 15:49:11 roberto Exp $
+** $Id: lfunc.h,v 2.15.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Auxiliary functions to manipulate prototypes and closures
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/lgc.c b/source/extern/lua/lgc.c
index 973c269..db4df82 100644
--- a/source/extern/lua/lgc.c
+++ b/source/extern/lua/lgc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 2.205 2015/03/25 13:42:19 roberto Exp $
+** $Id: lgc.c,v 2.215.1.2 2017/08/31 16:15:27 roberto Exp $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -114,8 +114,13 @@ static void reallymarkobject (global_State *g, GCObject *o);
 
 
 /*
-** if key is not marked, mark its entry as dead (therefore removing it
-** from the table)
+** If key is not marked, mark its entry as dead. This allows key to be
+** collected, but keeps its entry in the table.  A dead node is needed
+** when Lua looks up for a key (it may be part of a chain) and when
+** traversing a weak table (key might be removed from the table during
+** traversal). Other places never manipulate dead keys, because its
+** associated nil value is enough to signal that the entry is logically
+** empty.
 */
 static void removeentry (Node *n) {
   lua_assert(ttisnil(gval(n)));
@@ -462,7 +467,7 @@ static lu_mem traversetable (global_State *g, Table *h) {
   else  /* not weak */
     traversestrongtable(g, h);
   return sizeof(Table) + sizeof(TValue) * h->sizearray +
-                         sizeof(Node) * cast(size_t, sizenode(h));
+                         sizeof(Node) * cast(size_t, allocsizenode(h));
 }
 
 
@@ -534,7 +539,7 @@ static lu_mem traversethread (global_State *g, lua_State *th) {
     StkId lim = th->stack + th->stacksize;  /* real end of stack */
     for (; o < lim; o++)  /* clear not-marked stack slice */
       setnilvalue(o);
-    /* 'remarkupvals' may have removed thread from 'twups' list */ 
+    /* 'remarkupvals' may have removed thread from 'twups' list */
     if (!isintwups(th) && th->openupval != NULL) {
       th->twups = g->twups;  /* link it back to the list */
       g->twups = th;
@@ -542,7 +547,8 @@ static lu_mem traversethread (global_State *g, lua_State *th) {
   }
   else if (g->gckind != KGC_EMERGENCY)
     luaD_shrinkstack(th); /* do not change stack in emergency cycle */
-  return (sizeof(lua_State) + sizeof(TValue) * th->stacksize);
+  return (sizeof(lua_State) + sizeof(TValue) * th->stacksize +
+          sizeof(CallInfo) * th->nci);
 }
 
 
@@ -637,8 +643,9 @@ static void clearkeys (global_State *g, GCObject *l, GCObject *f) {
     for (n = gnode(h, 0); n < limit; n++) {
       if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) {
         setnilvalue(gval(n));  /* remove value ... */
-        removeentry(n);  /* and remove entry from table */
       }
+      if (ttisnil(gval(n)))  /* is entry empty? */
+        removeentry(n);  /* remove entry from table */
     }
   }
 }
@@ -748,14 +755,11 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
 /*
 ** sweep a list until a live object (or end of list)
 */
-static GCObject **sweeptolive (lua_State *L, GCObject **p, int *n) {
+static GCObject **sweeptolive (lua_State *L, GCObject **p) {
   GCObject **old = p;
-  int i = 0;
   do {
-    i++;
     p = sweeplist(L, p, 1);
   } while (p == old);
-  if (n) *n += i;
   return p;
 }
 
@@ -769,12 +773,11 @@ static GCObject **sweeptolive (lua_State *L, GCObject **p, int *n) {
 */
 
 /*
-** If possible, free concatenation buffer and shrink string table
+** If possible, shrink string table
 */
 static void checkSizes (lua_State *L, global_State *g) {
   if (g->gckind != KGC_EMERGENCY) {
     l_mem olddebt = g->GCdebt;
-    luaZ_freebuffer(L, &g->buff);  /* free concatenation buffer */
     if (g->strt.nuse < g->strt.size / 4)  /* string table too big? */
       luaS_resize(L, g->strt.size / 2);  /* shrink it a little */
     g->GCestimate += g->GCdebt - olddebt;  /* update estimate */
@@ -797,7 +800,7 @@ static GCObject *udata2finalize (global_State *g) {
 
 static void dothecall (lua_State *L, void *ud) {
   UNUSED(ud);
-  luaD_call(L, L->top - 2, 0, 0);
+  luaD_callnoyield(L, L->top - 2, 0);
 }
 
 
@@ -816,7 +819,9 @@ static void GCTM (lua_State *L, int propagateerrors) {
     setobj2s(L, L->top, tm);  /* push finalizer... */
     setobj2s(L, L->top + 1, &v);  /* ... and its argument */
     L->top += 2;  /* and (next line) call the finalizer */
+    L->ci->callstatus |= CIST_FIN;  /* will run a finalizer */
     status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
+    L->ci->callstatus &= ~CIST_FIN;  /* not running a finalizer anymore */
     L->allowhook = oldah;  /* restore hooks */
     g->gcrunning = running;  /* restore state */
     if (status != LUA_OK && propagateerrors) {  /* error while running __gc? */
@@ -851,10 +856,10 @@ static int runafewfinalizers (lua_State *L) {
 /*
 ** call all pending finalizers
 */
-static void callallpendingfinalizers (lua_State *L, int propagateerrors) {
+static void callallpendingfinalizers (lua_State *L) {
   global_State *g = G(L);
   while (g->tobefnz)
-    GCTM(L, propagateerrors);
+    GCTM(L, 0);
 }
 
 
@@ -904,7 +909,7 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
     if (issweepphase(g)) {
       makewhite(g, o);  /* "sweep" object 'o' */
       if (g->sweepgc == &o->next)  /* should not remove 'sweepgc' object */
-        g->sweepgc = sweeptolive(L, g->sweepgc, NULL);  /* change 'sweepgc' */
+        g->sweepgc = sweeptolive(L, g->sweepgc);  /* change 'sweepgc' */
     }
     /* search for pointer pointing to 'o' */
     for (p = &g->allgc; *p != o; p = &(*p)->next) { /* empty */ }
@@ -946,19 +951,16 @@ static void setpause (global_State *g) {
 
 /*
 ** Enter first sweep phase.
-** The call to 'sweeptolive' makes pointer point to an object inside
-** the list (instead of to the header), so that the real sweep do not
-** need to skip objects created between "now" and the start of the real
-** sweep.
-** Returns how many objects it swept.
+** The call to 'sweeplist' tries to make pointer point to an object
+** inside the list (instead of to the header), so that the real sweep do
+** not need to skip objects created between "now" and the start of the
+** real sweep.
 */
-static int entersweep (lua_State *L) {
+static void entersweep (lua_State *L) {
   global_State *g = G(L);
-  int n = 0;
   g->gcstate = GCSswpallgc;
   lua_assert(g->sweepgc == NULL);
-  g->sweepgc = sweeptolive(L, &g->allgc, &n);
-  return n;
+  g->sweepgc = sweeplist(L, &g->allgc, 1);
 }
 
 
@@ -966,7 +968,7 @@ void luaC_freeallobjects (lua_State *L) {
   global_State *g = G(L);
   separatetobefnz(g, 1);  /* separate all objects with finalizers */
   lua_assert(g->finobj == NULL);
-  callallpendingfinalizers(L, 0);
+  callallpendingfinalizers(L);
   lua_assert(g->tobefnz == NULL);
   g->currentwhite = WHITEBITS; /* this "white" makes all objects look dead */
   g->gckind = KGC_NORMAL;
@@ -1059,12 +1061,11 @@ static lu_mem singlestep (lua_State *L) {
     }
     case GCSatomic: {
       lu_mem work;
-      int sw;
       propagateall(g);  /* make sure gray list is empty */
       work = atomic(L);  /* work is what was traversed by 'atomic' */
-      sw = entersweep(L);
+      entersweep(L);
       g->GCestimate = gettotalbytes(g);  /* first estimate */;
-      return work + sw * GCSWEEPCOST;
+      return work;
     }
     case GCSswpallgc: {  /* sweep "regular" objects */
       return sweepstep(L, g, GCSswpfinobj, &g->finobj);
@@ -1114,9 +1115,12 @@ void luaC_runtilstate (lua_State *L, int statesmask) {
 static l_mem getdebt (global_State *g) {
   l_mem debt = g->GCdebt;
   int stepmul = g->gcstepmul;
-  debt = (debt / STEPMULADJ) + 1;
-  debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM;
-  return debt;
+  if (debt <= 0) return 0;  /* minimal debt */
+  else {
+    debt = (debt / STEPMULADJ) + 1;
+    debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM;
+    return debt;
+  }
 }
 
 /*
diff --git a/source/extern/lua/lgc.h b/source/extern/lua/lgc.h
index 0eedf84..425cd7c 100644
--- a/source/extern/lua/lgc.h
+++ b/source/extern/lua/lgc.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.h,v 2.86 2014/10/25 11:50:46 roberto Exp $
+** $Id: lgc.h,v 2.91.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -101,26 +101,35 @@
 #define luaC_white(g)	cast(lu_byte, (g)->currentwhite & WHITEBITS)
 
 
-#define luaC_condGC(L,c) \
-	{if (G(L)->GCdebt > 0) {c;}; condchangemem(L);}
-#define luaC_checkGC(L)		luaC_condGC(L, luaC_step(L);)
+/*
+** Does one step of collection when debt becomes positive. 'pre'/'pos'
+** allows some adjustments to be done only when needed. macro
+** 'condchangemem' is used only for heavy tests (forcing a full
+** GC cycle on every opportunity)
+*/
+#define luaC_condGC(L,pre,pos) \
+	{ if (G(L)->GCdebt > 0) { pre; luaC_step(L); pos;}; \
+	  condchangemem(L,pre,pos); }
+
+/* more often than not, 'pre'/'pos' are empty */
+#define luaC_checkGC(L)		luaC_condGC(L,(void)0,(void)0)
 
 
-#define luaC_barrier(L,p,v) {  \
-	if (iscollectable(v) && isblack(p) && iswhite(gcvalue(v)))  \
-	luaC_barrier_(L,obj2gco(p),gcvalue(v)); }
+#define luaC_barrier(L,p,v) (  \
+	(iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ?  \
+	luaC_barrier_(L,obj2gco(p),gcvalue(v)) : cast_void(0))
 
-#define luaC_barrierback(L,p,v) {  \
-	if (iscollectable(v) && isblack(p) && iswhite(gcvalue(v)))  \
-	luaC_barrierback_(L,p); }
+#define luaC_barrierback(L,p,v) (  \
+	(iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ? \
+	luaC_barrierback_(L,p) : cast_void(0))
 
-#define luaC_objbarrier(L,p,o) {  \
-	if (isblack(p) && iswhite(o)) \
-		luaC_barrier_(L,obj2gco(p),obj2gco(o)); }
+#define luaC_objbarrier(L,p,o) (  \
+	(isblack(p) && iswhite(o)) ? \
+	luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0))
 
-#define luaC_upvalbarrier(L,uv) \
-  { if (iscollectable((uv)->v) && !upisopen(uv)) \
-         luaC_upvalbarrier_(L,uv); }
+#define luaC_upvalbarrier(L,uv) ( \
+	(iscollectable((uv)->v) && !upisopen(uv)) ? \
+         luaC_upvalbarrier_(L,uv) : cast_void(0))
 
 LUAI_FUNC void luaC_fix (lua_State *L, GCObject *o);
 LUAI_FUNC void luaC_freeallobjects (lua_State *L);
diff --git a/source/extern/lua/linit.c b/source/extern/lua/linit.c
index 8ce94cc..480da52 100644
--- a/source/extern/lua/linit.c
+++ b/source/extern/lua/linit.c
@@ -1,5 +1,5 @@
 /*
-** $Id: linit.c,v 1.38 2015/01/05 13:48:33 roberto Exp $
+** $Id: linit.c,v 1.39.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Initialization of libraries for lua.c and other clients
 ** See Copyright Notice in lua.h
 */
@@ -18,10 +18,10 @@
 ** open the library, which is already linked to the application.
 ** For that, do the following code:
 **
-**  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
+**  luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
 **  lua_pushcfunction(L, luaopen_modname);
 **  lua_setfield(L, -2, modname);
-**  lua_pop(L, 1);  // remove _PRELOAD table
+**  lua_pop(L, 1);  // remove PRELOAD table
 */
 
 #include "lprefix.h"
diff --git a/source/extern/lua/liolib.c b/source/extern/lua/liolib.c
index 193cac6..027d4bd 100644
--- a/source/extern/lua/liolib.c
+++ b/source/extern/lua/liolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: liolib.c,v 2.144 2015/04/03 18:41:57 roberto Exp $
+** $Id: liolib.c,v 2.151.1.1 2017/04/19 17:29:57 roberto Exp $
 ** Standard I/O (and system) library
 ** See Copyright Notice in lua.h
 */
@@ -23,18 +23,25 @@
 #include "lualib.h"
 
 
-#if !defined(l_checkmode)
+
 
 /*
-** Check whether 'mode' matches '[rwa]%+?b?'.
 ** Change this macro to accept other modes for 'fopen' besides
 ** the standard ones.
 */
-#define l_checkmode(mode) \
-	(*mode != '\0' && strchr("rwa", *(mode++)) != NULL &&	\
-	(*mode != '+' || ++mode) &&  /* skip if char is '+' */	\
-	(*mode != 'b' || ++mode) &&  /* skip if char is 'b' */	\
-	(*mode == '\0'))
+#if !defined(l_checkmode)
+
+/* accepted extensions to 'mode' in 'fopen' */
+#if !defined(L_MODEEXT)
+#define L_MODEEXT	"b"
+#endif
+
+/* Check whether 'mode' matches '[rwa]%+?[L_MODEEXT]*' */
+static int l_checkmode (const char *mode) {
+  return (*mode != '\0' && strchr("rwa", *(mode++)) != NULL &&
+         (*mode != '+' || (++mode, 1)) &&  /* skip if char is '+' */
+         (strspn(mode, L_MODEEXT) == strlen(mode)));  /* check extensions */
+}
 
 #endif
 
@@ -176,7 +183,7 @@ static FILE *tofile (lua_State *L) {
 /*
 ** When creating file handles, always creates a 'closed' file handle
 ** before opening the actual file; so, if there is a memory error, the
-** file is not left opened.
+** handle is in a consistent state.
 */
 static LStream *newprefile (lua_State *L) {
   LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream));
@@ -199,11 +206,16 @@ static int aux_close (lua_State *L) {
 }
 
 
+static int f_close (lua_State *L) {
+  tofile(L);  /* make sure argument is an open stream */
+  return aux_close(L);
+}
+
+
 static int io_close (lua_State *L) {
   if (lua_isnone(L, 1))  /* no argument? */
     lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT);  /* use standard output */
-  tofile(L);  /* make sure argument is an open stream */
-  return aux_close(L);
+  return f_close(L);
 }
 
 
@@ -265,6 +277,8 @@ static int io_popen (lua_State *L) {
   const char *filename = luaL_checkstring(L, 1);
   const char *mode = luaL_optstring(L, 2, "r");
   LStream *p = newprefile(L);
+  luaL_argcheck(L, ((mode[0] == 'r' || mode[0] == 'w') && mode[1] == '\0'),
+                   2, "invalid mode");
   p->f = l_popen(L, filename, mode);
   p->closef = &io_pclose;
   return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
@@ -318,8 +332,15 @@ static int io_output (lua_State *L) {
 static int io_readline (lua_State *L);
 
 
+/*
+** maximum number of arguments to 'f:lines'/'io.lines' (it + 3 must fit
+** in the limit for upvalues of a closure)
+*/
+#define MAXARGLINE	250
+
 static void aux_lines (lua_State *L, int toclose) {
   int n = lua_gettop(L) - 1;  /* number of arguments to read */
+  luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments");
   lua_pushinteger(L, n);  /* number of arguments to read */
   lua_pushboolean(L, toclose);  /* close/not close file when finished */
   lua_rotate(L, 2, 2);  /* move 'n' and 'toclose' to their positions */
@@ -362,14 +383,17 @@ static int io_lines (lua_State *L) {
 
 
 /* maximum length of a numeral */
-#define MAXRN		200
+#if !defined (L_MAXLENNUM)
+#define L_MAXLENNUM     200
+#endif
+
 
 /* auxiliary structure used by 'read_number' */
 typedef struct {
   FILE *f;  /* file being read */
   int c;  /* current character (look ahead) */
   int n;  /* number of elements in buffer 'buff' */
-  char buff[MAXRN + 1];  /* +1 for ending '\0' */
+  char buff[L_MAXLENNUM + 1];  /* +1 for ending '\0' */
 } RN;
 
 
@@ -377,7 +401,7 @@ typedef struct {
 ** Add current char to buffer (if not out of space) and read next one
 */
 static int nextc (RN *rn) {
-  if (rn->n >= MAXRN) {  /* buffer overflow? */
+  if (rn->n >= L_MAXLENNUM) {  /* buffer overflow? */
     rn->buff[0] = '\0';  /* invalidate result */
     return 0;  /* fail */
   }
@@ -390,10 +414,10 @@ static int nextc (RN *rn) {
 
 
 /*
-** Accept current char if it is in 'set' (of size 1 or 2)
+** Accept current char if it is in 'set' (of size 2)
 */
 static int test2 (RN *rn, const char *set) {
-  if (rn->c == set[0] || (rn->c == set[1] && rn->c != '\0'))
+  if (rn->c == set[0] || rn->c == set[1])
     return nextc(rn);
   else return 0;
 }
@@ -422,11 +446,11 @@ static int read_number (lua_State *L, FILE *f) {
   char decp[2];
   rn.f = f; rn.n = 0;
   decp[0] = lua_getlocaledecpoint();  /* get decimal point from locale */
-  decp[1] = '\0';
+  decp[1] = '.';  /* always accept a dot */
   l_lockfile(rn.f);
   do { rn.c = l_getc(rn.f); } while (isspace(rn.c));  /* skip spaces */
   test2(&rn, "-+");  /* optional signal */
-  if (test2(&rn, "0")) {
+  if (test2(&rn, "00")) {
     if (test2(&rn, "xX")) hex = 1;  /* numeral is hexadecimal */
     else count = 1;  /* count initial '0' as a valid digit */
   }
@@ -462,7 +486,7 @@ static int read_line (lua_State *L, FILE *f, int chop) {
   int c = '\0';
   luaL_buffinit(L, &b);
   while (c != EOF && c != '\n') {  /* repeat until end of line */
-    char *buff = luaL_prepbuffer(&b);  /* pre-allocate buffer */
+    char *buff = luaL_prepbuffer(&b);  /* preallocate buffer */
     int i = 0;
     l_lockfile(f);  /* no memory errors can happen inside the lock */
     while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n')
@@ -483,7 +507,7 @@ static void read_all (lua_State *L, FILE *f) {
   luaL_Buffer b;
   luaL_buffinit(L, &b);
   do {  /* read file in chunks of LUAL_BUFFERSIZE bytes */
-    char *p = luaL_prepbuffsize(&b, LUAL_BUFFERSIZE);
+    char *p = luaL_prepbuffer(&b);
     nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f);
     luaL_addsize(&b, nr);
   } while (nr == LUAL_BUFFERSIZE);
@@ -602,8 +626,10 @@ static int g_write (lua_State *L, FILE *f, int arg) {
     if (lua_type(L, arg) == LUA_TNUMBER) {
       /* optimization: could be done exactly as for strings */
       int len = lua_isinteger(L, arg)
-                ? fprintf(f, LUA_INTEGER_FMT, lua_tointeger(L, arg))
-                : fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg));
+                ? fprintf(f, LUA_INTEGER_FMT,
+                             (LUAI_UACINT)lua_tointeger(L, arg))
+                : fprintf(f, LUA_NUMBER_FMT,
+                             (LUAI_UACNUMBER)lua_tonumber(L, arg));
       status = status && (len > 0);
     }
     else {
@@ -693,7 +719,7 @@ static const luaL_Reg iolib[] = {
 ** methods for file handles
 */
 static const luaL_Reg flib[] = {
-  {"close", io_close},
+  {"close", f_close},
   {"flush", f_flush},
   {"lines", f_lines},
   {"read", f_read},
diff --git a/source/extern/lua/llex.c b/source/extern/lua/llex.c
index c35bd55..b6d9a46 100644
--- a/source/extern/lua/llex.c
+++ b/source/extern/lua/llex.c
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.c,v 2.93 2015/05/22 17:45:56 roberto Exp $
+** $Id: llex.c,v 2.96.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -162,7 +162,6 @@ static void inclinenumber (LexState *ls) {
 void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source,
                     int firstchar) {
   ls->t.token = 0;
-  ls->decpoint = '.';
   ls->L = L;
   ls->current = firstchar;
   ls->lookahead.token = TK_EOS;  /* no look-ahead token */
@@ -207,37 +206,6 @@ static int check_next2 (LexState *ls, const char *set) {
 }
 
 
-/*
-** change all characters 'from' in buffer to 'to'
-*/
-static void buffreplace (LexState *ls, char from, char to) {
-  if (from != to) {
-    size_t n = luaZ_bufflen(ls->buff);
-    char *p = luaZ_buffer(ls->buff);
-    while (n--)
-      if (p[n] == from) p[n] = to;
-  }
-}
-
-
-#define buff2num(b,o)	(luaO_str2num(luaZ_buffer(b), o) != 0)
-
-/*
-** in case of format error, try to change decimal point separator to
-** the one defined in the current locale and check again
-*/
-static void trydecpoint (LexState *ls, TValue *o) {
-  char old = ls->decpoint;
-  ls->decpoint = lua_getlocaledecpoint();
-  buffreplace(ls, old, ls->decpoint);  /* try new decimal separator */
-  if (!buff2num(ls->buff, o)) {
-    /* format error with correct decimal point: no more options */
-    buffreplace(ls, ls->decpoint, '.');  /* undo change (for error message) */
-    lexerror(ls, "malformed number", TK_FLT);
-  }
-}
-
-
 /* LUA_NUMBER */
 /*
 ** this function is quite liberal in what it accepts, as 'luaO_str2num'
@@ -261,9 +229,8 @@ static int read_numeral (LexState *ls, SemInfo *seminfo) {
     else break;
   }
   save(ls, '\0');
-  buffreplace(ls, '.', ls->decpoint);  /* follow locale for decimal point */
-  if (!buff2num(ls->buff, &obj))  /* format error? */
-    trydecpoint(ls, &obj); /* try to update decimal point separator */
+  if (luaO_str2num(luaZ_buffer(ls->buff), &obj) == 0)  /* format error? */
+    lexerror(ls, "malformed number", TK_FLT);
   if (ttisinteger(&obj)) {
     seminfo->i = ivalue(&obj);
     return TK_INT;
@@ -277,12 +244,12 @@ static int read_numeral (LexState *ls, SemInfo *seminfo) {
 
 
 /*
-** skip a sequence '[=*[' or ']=*]'; if sequence is wellformed, return
-** its number of '='s; otherwise, return a negative number (-1 iff there
-** are no '='s after initial bracket)
+** reads a sequence '[=*[' or ']=*]', leaving the last bracket.
+** If sequence is well formed, return its number of '='s + 2; otherwise,
+** return 1 if there is no '='s or 0 otherwise (an unfinished '[==...').
 */
-static int skip_sep (LexState *ls) {
-  int count = 0;
+static size_t skip_sep (LexState *ls) {
+  size_t count = 0;
   int s = ls->current;
   lua_assert(s == '[' || s == ']');
   save_and_next(ls);
@@ -290,11 +257,14 @@ static int skip_sep (LexState *ls) {
     save_and_next(ls);
     count++;
   }
-  return (ls->current == s) ? count : (-count) - 1;
+  return (ls->current == s) ? count + 2
+         : (count == 0) ? 1
+         : 0;
+
 }
 
 
-static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
+static void read_long_string (LexState *ls, SemInfo *seminfo, size_t sep) {
   int line = ls->linenumber;  /* initial line (for error message) */
   save_and_next(ls);  /* skip 2nd '[' */
   if (currIsNewline(ls))  /* string starts with a newline? */
@@ -328,8 +298,8 @@ static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
     }
   } endloop:
   if (seminfo)
-    seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep),
-                                     luaZ_bufflen(ls->buff) - 2*(2 + sep));
+    seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + sep,
+                                     luaZ_bufflen(ls->buff) - 2 * sep);
 }
 
 
@@ -477,9 +447,9 @@ static int llex (LexState *ls, SemInfo *seminfo) {
         /* else is a comment */
         next(ls);
         if (ls->current == '[') {  /* long comment? */
-          int sep = skip_sep(ls);
+          size_t sep = skip_sep(ls);
           luaZ_resetbuffer(ls->buff);  /* 'skip_sep' may dirty the buffer */
-          if (sep >= 0) {
+          if (sep >= 2) {
             read_long_string(ls, NULL, sep);  /* skip long comment */
             luaZ_resetbuffer(ls->buff);  /* previous call may dirty the buff. */
             break;
@@ -491,12 +461,12 @@ static int llex (LexState *ls, SemInfo *seminfo) {
         break;
       }
       case '[': {  /* long string or simply '[' */
-        int sep = skip_sep(ls);
-        if (sep >= 0) {
+        size_t sep = skip_sep(ls);
+        if (sep >= 2) {
           read_long_string(ls, seminfo, sep);
           return TK_STRING;
         }
-        else if (sep != -1)  /* '[=...' missing second bracket */
+        else if (sep == 0)  /* '[=...' missing second bracket */
           lexerror(ls, "invalid long string delimiter", TK_STRING);
         return '[';
       }
diff --git a/source/extern/lua/llex.h b/source/extern/lua/llex.h
index afb40b5..2ed0af6 100644
--- a/source/extern/lua/llex.h
+++ b/source/extern/lua/llex.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.h,v 1.78 2014/10/29 15:38:24 roberto Exp $
+** $Id: llex.h,v 1.79.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -69,7 +69,6 @@ typedef struct LexState {
   struct Dyndata *dyd;  /* dynamic structures used by the parser */
   TString *source;  /* current source name */
   TString *envn;  /* environment variable name */
-  char decpoint;  /* locale decimal point */
 } LexState;
 
 
diff --git a/source/extern/lua/llimits.h b/source/extern/lua/llimits.h
index 277c724..d1036f6 100644
--- a/source/extern/lua/llimits.h
+++ b/source/extern/lua/llimits.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llimits.h,v 1.135 2015/06/09 14:21:00 roberto Exp $
+** $Id: llimits.h,v 1.141.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Limits, basic types, and some other 'installation-dependent' definitions
 ** See Copyright Notice in lua.h
 */
@@ -64,7 +64,13 @@ typedef unsigned char lu_byte;
 #if defined(LUAI_USER_ALIGNMENT_T)
 typedef LUAI_USER_ALIGNMENT_T L_Umaxalign;
 #else
-typedef union { double u; void *s; lua_Integer i; long l; } L_Umaxalign;
+typedef union {
+  lua_Number n;
+  double u;
+  void *s;
+  lua_Integer i;
+  long l;
+} L_Umaxalign;
 #endif
 
 
@@ -78,7 +84,7 @@ typedef LUAI_UACINT l_uacInt;
 #if defined(lua_assert)
 #define check_exp(c,e)		(lua_assert(c), (e))
 /* to avoid problems with conditions too long */
-#define lua_longassert(c)	{ if (!(c)) lua_assert(0); }
+#define lua_longassert(c)	((c) ? (void)0 : lua_assert(0))
 #else
 #define lua_assert(c)		((void)0)
 #define check_exp(c,e)		(e)
@@ -184,10 +190,13 @@ typedef unsigned long Instruction;
 
 
 /*
-** Size of cache for strings in the API (better be a prime)
+** Size of cache for strings in the API. 'N' is the number of
+** sets (better be a prime) and "M" is the size of each set (M == 1
+** makes a direct cache.)
 */
-#if !defined(STRCACHE_SIZE)
-#define STRCACHE_SIZE		127
+#if !defined(STRCACHE_N)
+#define STRCACHE_N		53
+#define STRCACHE_M		2
 #endif
 
 
@@ -198,7 +207,7 @@ typedef unsigned long Instruction;
 
 
 /*
-** macros that are executed whenether program enters the Lua core
+** macros that are executed whenever program enters the Lua core
 ** ('lua_lock') and leaves the core ('lua_unlock')
 */
 #if !defined(lua_lock)
@@ -297,17 +306,18 @@ typedef unsigned long Instruction;
 ** macro to control inclusion of some hard tests on stack reallocation
 */
 #if !defined(HARDSTACKTESTS)
-#define condmovestack(L)	((void)0)
+#define condmovestack(L,pre,pos)	((void)0)
 #else
 /* realloc stack keeping its size */
-#define condmovestack(L)	luaD_reallocstack((L), (L)->stacksize)
+#define condmovestack(L,pre,pos)  \
+	{ int sz_ = (L)->stacksize; pre; luaD_reallocstack((L), sz_); pos; }
 #endif
 
 #if !defined(HARDMEMTESTS)
-#define condchangemem(L)	condmovestack(L)
+#define condchangemem(L,pre,pos)	((void)0)
 #else
-#define condchangemem(L)  \
-	((void)(!(G(L)->gcrunning) || (luaC_fullgc(L, 0), 1)))
+#define condchangemem(L,pre,pos)  \
+	{ if (G(L)->gcrunning) { pre; luaC_fullgc(L, 0); pos; } }
 #endif
 
 #endif
diff --git a/source/extern/lua/lmathlib.c b/source/extern/lua/lmathlib.c
index 4f2ec60..7ef7e59 100644
--- a/source/extern/lua/lmathlib.c
+++ b/source/extern/lua/lmathlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmathlib.c,v 1.115 2015/03/12 14:04:04 roberto Exp $
+** $Id: lmathlib.c,v 1.119.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Standard mathematical library
 ** See Copyright Notice in lua.h
 */
@@ -39,7 +39,7 @@
 static int math_abs (lua_State *L) {
   if (lua_isinteger(L, 1)) {
     lua_Integer n = lua_tointeger(L, 1);
-    if (n < 0) n = (lua_Integer)(0u - n);
+    if (n < 0) n = (lua_Integer)(0u - (lua_Unsigned)n);
     lua_pushinteger(L, n);
   }
   else
@@ -184,10 +184,13 @@ static int math_log (lua_State *L) {
   else {
     lua_Number base = luaL_checknumber(L, 2);
 #if !defined(LUA_USE_C89)
-    if (base == 2.0) res = l_mathop(log2)(x); else
+    if (base == l_mathop(2.0))
+      res = l_mathop(log2)(x); else
 #endif
-    if (base == 10.0) res = l_mathop(log10)(x);
-    else res = l_mathop(log)(x)/l_mathop(log)(base);
+    if (base == l_mathop(10.0))
+      res = l_mathop(log10)(x);
+    else
+      res = l_mathop(log)(x)/l_mathop(log)(base);
   }
   lua_pushnumber(L, res);
   return 1;
@@ -262,7 +265,7 @@ static int math_random (lua_State *L) {
     default: return luaL_error(L, "wrong number of arguments");
   }
   /* random integer in the interval [low, up] */
-  luaL_argcheck(L, low <= up, 1, "interval is empty"); 
+  luaL_argcheck(L, low <= up, 1, "interval is empty");
   luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,
                    "interval too large");
   r *= (double)(up - low) + 1.0;
@@ -273,7 +276,7 @@ static int math_random (lua_State *L) {
 
 static int math_randomseed (lua_State *L) {
   l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1));
-  (void)rand(); /* discard first value to avoid undesirable correlations */
+  (void)l_rand(); /* discard first value to avoid undesirable correlations */
   return 0;
 }
 
@@ -281,9 +284,9 @@ static int math_randomseed (lua_State *L) {
 static int math_type (lua_State *L) {
   if (lua_type(L, 1) == LUA_TNUMBER) {
       if (lua_isinteger(L, 1))
-        lua_pushliteral(L, "integer"); 
+        lua_pushliteral(L, "integer");
       else
-        lua_pushliteral(L, "float"); 
+        lua_pushliteral(L, "float");
   }
   else {
     luaL_checkany(L, 1);
diff --git a/source/extern/lua/lmem.c b/source/extern/lua/lmem.c
index 0a0476c..0241cc3 100644
--- a/source/extern/lua/lmem.c
+++ b/source/extern/lua/lmem.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.c,v 1.91 2015/03/06 19:45:54 roberto Exp $
+** $Id: lmem.c,v 1.91.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/lmem.h b/source/extern/lua/lmem.h
index 30f4848..357b1e4 100644
--- a/source/extern/lua/lmem.h
+++ b/source/extern/lua/lmem.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h,v 1.43 2014/12/19 17:26:14 roberto Exp $
+** $Id: lmem.h,v 1.43.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/loadlib.c b/source/extern/lua/loadlib.c
index bbf8f67..45f44d3 100644
--- a/source/extern/lua/loadlib.c
+++ b/source/extern/lua/loadlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: loadlib.c,v 1.126 2015/02/16 13:14:33 roberto Exp $
+** $Id: loadlib.c,v 1.130.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Dynamic library loader for Lua
 ** See Copyright Notice in lua.h
 **
@@ -25,40 +25,9 @@
 
 
 /*
-** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment
-** variables that Lua check to set its paths.
-*/
-#if !defined(LUA_PATH_VAR)
-#define LUA_PATH_VAR	"LUA_PATH"
-#endif
-
-#if !defined(LUA_CPATH_VAR)
-#define LUA_CPATH_VAR	"LUA_CPATH"
-#endif
-
-#define LUA_PATHSUFFIX		"_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
-
-#define LUA_PATHVARVERSION		LUA_PATH_VAR LUA_PATHSUFFIX
-#define LUA_CPATHVARVERSION		LUA_CPATH_VAR LUA_PATHSUFFIX
-
-/*
-** LUA_PATH_SEP is the character that separates templates in a path.
-** LUA_PATH_MARK is the string that marks the substitution points in a
-** template.
-** LUA_EXEC_DIR in a Windows path is replaced by the executable's
-** directory.
 ** LUA_IGMARK is a mark to ignore all before it when building the
 ** luaopen_ function name.
 */
-#if !defined (LUA_PATH_SEP)
-#define LUA_PATH_SEP		";"
-#endif
-#if !defined (LUA_PATH_MARK)
-#define LUA_PATH_MARK		"?"
-#endif
-#if !defined (LUA_EXEC_DIR)
-#define LUA_EXEC_DIR		"!"
-#endif
 #if !defined (LUA_IGMARK)
 #define LUA_IGMARK		"-"
 #endif
@@ -94,7 +63,8 @@ static const int CLIBS = 0;
 
 #define LIB_FAIL	"open"
 
-#define setprogdir(L)		((void)0)
+
+#define setprogdir(L)           ((void)0)
 
 
 /*
@@ -179,7 +149,6 @@ static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
 
 #include <windows.h>
 
-#undef setprogdir
 
 /*
 ** optional flags for LoadLibraryEx
@@ -189,21 +158,30 @@ static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
 #endif
 
 
+#undef setprogdir
+
+
+/*
+** Replace in the path (on the top of the stack) any occurrence
+** of LUA_EXEC_DIR with the executable's path.
+*/
 static void setprogdir (lua_State *L) {
   char buff[MAX_PATH + 1];
   char *lb;
   DWORD nsize = sizeof(buff)/sizeof(char);
-  DWORD n = GetModuleFileNameA(NULL, buff, nsize);
+  DWORD n = GetModuleFileNameA(NULL, buff, nsize);  /* get exec. name */
   if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
     luaL_error(L, "unable to get ModuleFileName");
   else {
-    *lb = '\0';
+    *lb = '\0';  /* cut name on the last '\\' to get the path */
     luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff);
     lua_remove(L, -2);  /* remove original string */
   }
 }
 
 
+
+
 static void pusherror (lua_State *L) {
   int error = GetLastError();
   char buffer[128];
@@ -272,6 +250,67 @@ static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
 #endif				/* } */
 
 
+/*
+** {==================================================================
+** Set Paths
+** ===================================================================
+*/
+
+/*
+** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment
+** variables that Lua check to set its paths.
+*/
+#if !defined(LUA_PATH_VAR)
+#define LUA_PATH_VAR    "LUA_PATH"
+#endif
+
+#if !defined(LUA_CPATH_VAR)
+#define LUA_CPATH_VAR   "LUA_CPATH"
+#endif
+
+
+#define AUXMARK         "\1"	/* auxiliary mark */
+
+
+/*
+** return registry.LUA_NOENV as a boolean
+*/
+static int noenv (lua_State *L) {
+  int b;
+  lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
+  b = lua_toboolean(L, -1);
+  lua_pop(L, 1);  /* remove value */
+  return b;
+}
+
+
+/*
+** Set a path
+*/
+static void setpath (lua_State *L, const char *fieldname,
+                                   const char *envname,
+                                   const char *dft) {
+  const char *nver = lua_pushfstring(L, "%s%s", envname, LUA_VERSUFFIX);
+  const char *path = getenv(nver);  /* use versioned name */
+  if (path == NULL)  /* no environment variable? */
+    path = getenv(envname);  /* try unversioned name */
+  if (path == NULL || noenv(L))  /* no environment variable? */
+    lua_pushstring(L, dft);  /* use default */
+  else {
+    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
+    path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
+                              LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
+    luaL_gsub(L, path, AUXMARK, dft);
+    lua_remove(L, -2); /* remove result from 1st 'gsub' */
+  }
+  setprogdir(L);
+  lua_setfield(L, -3, fieldname);  /* package[fieldname] = path value */
+  lua_pop(L, 1);  /* pop versioned variable name */
+}
+
+/* }================================================================== */
+
+
 /*
 ** return registry.CLIBS[path]
 */
@@ -520,7 +559,7 @@ static int searcher_Croot (lua_State *L) {
 
 static int searcher_preload (lua_State *L) {
   const char *name = luaL_checkstring(L, 1);
-  lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
+  lua_getfield(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
   if (lua_getfield(L, -1, name) == LUA_TNIL)  /* not found? */
     lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
   return 1;
@@ -557,9 +596,9 @@ static void findloader (lua_State *L, const char *name) {
 
 static int ll_require (lua_State *L) {
   const char *name = luaL_checkstring(L, 1);
-  lua_settop(L, 1);  /* _LOADED table will be at index 2 */
-  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
-  lua_getfield(L, 2, name);  /* _LOADED[name] */
+  lua_settop(L, 1);  /* LOADED table will be at index 2 */
+  lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
+  lua_getfield(L, 2, name);  /* LOADED[name] */
   if (lua_toboolean(L, -1))  /* is it there? */
     return 1;  /* package is already loaded */
   /* else must load package */
@@ -569,11 +608,11 @@ static int ll_require (lua_State *L) {
   lua_insert(L, -2);  /* name is 1st argument (before search data) */
   lua_call(L, 2, 1);  /* run loader to load module */
   if (!lua_isnil(L, -1))  /* non-nil return? */
-    lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
+    lua_setfield(L, 2, name);  /* LOADED[name] = returned value */
   if (lua_getfield(L, 2, name) == LUA_TNIL) {   /* module set no value? */
     lua_pushboolean(L, 1);  /* use true as result */
     lua_pushvalue(L, -1);  /* extra copy to be returned */
-    lua_setfield(L, 2, name);  /* _LOADED[name] = true */
+    lua_setfield(L, 2, name);  /* LOADED[name] = true */
   }
   return 1;
 }
@@ -666,41 +705,6 @@ static int ll_seeall (lua_State *L) {
 
 
 
-/* auxiliary mark (for internal use) */
-#define AUXMARK		"\1"
-
-
-/*
-** return registry.LUA_NOENV as a boolean
-*/
-static int noenv (lua_State *L) {
-  int b;
-  lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
-  b = lua_toboolean(L, -1);
-  lua_pop(L, 1);  /* remove value */
-  return b;
-}
-
-
-static void setpath (lua_State *L, const char *fieldname, const char *envname1,
-                                   const char *envname2, const char *def) {
-  const char *path = getenv(envname1);
-  if (path == NULL)  /* no environment variable? */
-    path = getenv(envname2);  /* try alternative name */
-  if (path == NULL || noenv(L))  /* no environment variable? */
-    lua_pushstring(L, def);  /* use default */
-  else {
-    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
-    path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP,
-                              LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
-    luaL_gsub(L, path, AUXMARK, def);
-    lua_remove(L, -2);
-  }
-  setprogdir(L);
-  lua_setfield(L, -2, fieldname);
-}
-
-
 static const luaL_Reg pk_funcs[] = {
   {"loadlib", ll_loadlib},
   {"searchpath", ll_searchpath},
@@ -732,7 +736,7 @@ static void createsearcherstable (lua_State *L) {
   int i;
   /* create 'searchers' table */
   lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
-  /* fill it with pre-defined searchers */
+  /* fill it with predefined searchers */
   for (i=0; searchers[i] != NULL; i++) {
     lua_pushvalue(L, -2);  /* set 'package' as upvalue for all searchers */
     lua_pushcclosure(L, searchers[i], 1);
@@ -764,19 +768,18 @@ LUAMOD_API int luaopen_package (lua_State *L) {
   createclibstable(L);
   luaL_newlib(L, pk_funcs);  /* create 'package' table */
   createsearcherstable(L);
-  /* set field 'path' */
-  setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT);
-  /* set field 'cpath' */
-  setpath(L, "cpath", LUA_CPATHVARVERSION, LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
+  /* set paths */
+  setpath(L, "path", LUA_PATH_VAR, LUA_PATH_DEFAULT);
+  setpath(L, "cpath", LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
   /* store config information */
   lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
                      LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
   lua_setfield(L, -2, "config");
   /* set field 'loaded' */
-  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
   lua_setfield(L, -2, "loaded");
   /* set field 'preload' */
-  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
   lua_setfield(L, -2, "preload");
   lua_pushglobaltable(L);
   lua_pushvalue(L, -2);  /* set 'package' as upvalue for next lib */
diff --git a/source/extern/lua/lobject.c b/source/extern/lua/lobject.c
index 6c53b98..355bf58 100644
--- a/source/extern/lua/lobject.c
+++ b/source/extern/lua/lobject.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.c,v 2.104 2015/04/11 18:30:08 roberto Exp $
+** $Id: lobject.c,v 2.113.1.1 2017/04/19 17:29:57 roberto Exp $
 ** Some generic functions over Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -55,9 +55,7 @@ int luaO_int2fb (unsigned int x) {
 
 /* converts back */
 int luaO_fb2int (int x) {
-  int e = (x >> 3) & 0x1f;
-  if (e == 0) return x;
-  else return ((x & 7) + 8) << (e - 1);
+  return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
 }
 
 
@@ -245,20 +243,59 @@ static lua_Number lua_strx2number (const char *s, char **endptr) {
 /* }====================================================== */
 
 
-static const char *l_str2d (const char *s, lua_Number *result) {
+/* maximum length of a numeral */
+#if !defined (L_MAXLENNUM)
+#define L_MAXLENNUM	200
+#endif
+
+static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
   char *endptr;
-  if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
-    return NULL;
-  else if (strpbrk(s, "xX"))  /* hex? */
-    *result = lua_strx2number(s, &endptr);
-  else
-    *result = lua_str2number(s, &endptr);
-  if (endptr == s) return NULL;  /* nothing recognized */
-  while (lisspace(cast_uchar(*endptr))) endptr++;
-  return (*endptr == '\0' ? endptr : NULL);  /* OK if no trailing characters */
+  *result = (mode == 'x') ? lua_strx2number(s, &endptr)  /* try to convert */
+                          : lua_str2number(s, &endptr);
+  if (endptr == s) return NULL;  /* nothing recognized? */
+  while (lisspace(cast_uchar(*endptr))) endptr++;  /* skip trailing spaces */
+  return (*endptr == '\0') ? endptr : NULL;  /* OK if no trailing characters */
 }
 
 
+/*
+** Convert string 's' to a Lua number (put in 'result'). Return NULL
+** on fail or the address of the ending '\0' on success.
+** 'pmode' points to (and 'mode' contains) special things in the string:
+** - 'x'/'X' means an hexadecimal numeral
+** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
+** - '.' just optimizes the search for the common case (nothing special)
+** This function accepts both the current locale or a dot as the radix
+** mark. If the conversion fails, it may mean number has a dot but
+** locale accepts something else. In that case, the code copies 's'
+** to a buffer (because 's' is read-only), changes the dot to the
+** current locale radix mark, and tries to convert again.
+*/
+static const char *l_str2d (const char *s, lua_Number *result) {
+  const char *endptr;
+  const char *pmode = strpbrk(s, ".xXnN");
+  int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
+  if (mode == 'n')  /* reject 'inf' and 'nan' */
+    return NULL;
+  endptr = l_str2dloc(s, result, mode);  /* try to convert */
+  if (endptr == NULL) {  /* failed? may be a different locale */
+    char buff[L_MAXLENNUM + 1];
+    const char *pdot = strchr(s, '.');
+    if (strlen(s) > L_MAXLENNUM || pdot == NULL)
+      return NULL;  /* string too long or no dot; fail */
+    strcpy(buff, s);  /* copy string to buffer */
+    buff[pdot - s] = lua_getlocaledecpoint();  /* correct decimal point */
+    endptr = l_str2dloc(buff, result, mode);  /* try again */
+    if (endptr != NULL)
+      endptr = s + (endptr - buff);  /* make relative to 's' */
+  }
+  return endptr;
+}
+
+
+#define MAXBY10		cast(lua_Unsigned, LUA_MAXINTEGER / 10)
+#define MAXLASTD	cast_int(LUA_MAXINTEGER % 10)
+
 static const char *l_str2int (const char *s, lua_Integer *result) {
   lua_Unsigned a = 0;
   int empty = 1;
@@ -275,7 +312,10 @@ static const char *l_str2int (const char *s, lua_Integer *result) {
   }
   else {  /* decimal */
     for (; lisdigit(cast_uchar(*s)); s++) {
-      a = a * 10 + *s - '0';
+      int d = *s - '0';
+      if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg))  /* overflow? */
+        return NULL;  /* do not accept it (as integer) */
+      a = a * 10 + d;
       empty = 0;
     }
   }
@@ -333,9 +373,9 @@ void luaO_tostring (lua_State *L, StkId obj) {
   size_t len;
   lua_assert(ttisnumber(obj));
   if (ttisinteger(obj))
-    len = lua_integer2str(buff, ivalue(obj));
+    len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
   else {
-    len = lua_number2str(buff, fltvalue(obj));
+    len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
 #if !defined(LUA_COMPAT_FLOATSTRING)
     if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */
       buff[len++] = lua_getlocaledecpoint();
@@ -348,27 +388,29 @@ void luaO_tostring (lua_State *L, StkId obj) {
 
 
 static void pushstr (lua_State *L, const char *str, size_t l) {
-  setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
+  setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
+  luaD_inctop(L);
 }
 
 
-/* this function handles only '%d', '%c', '%f', '%p', and '%s' 
-   conventional formats, plus Lua-specific '%I' and '%U' */
+/*
+** this function handles only '%d', '%c', '%f', '%p', and '%s'
+   conventional formats, plus Lua-specific '%I' and '%U'
+*/
 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
   int n = 0;
   for (;;) {
     const char *e = strchr(fmt, '%');
     if (e == NULL) break;
-    luaD_checkstack(L, 2);  /* fmt + item */
     pushstr(L, fmt, e - fmt);
     switch (*(e+1)) {
-      case 's': {
+      case 's': {  /* zero-terminated string */
         const char *s = va_arg(argp, char *);
         if (s == NULL) s = "(null)";
         pushstr(L, s, strlen(s));
         break;
       }
-      case 'c': {
+      case 'c': {  /* an 'int' as a character */
         char buff = cast(char, va_arg(argp, int));
         if (lisprint(cast_uchar(buff)))
           pushstr(L, &buff, 1);
@@ -376,28 +418,29 @@ const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
           luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
         break;
       }
-      case 'd': {
-        setivalue(L->top++, va_arg(argp, int));
+      case 'd': {  /* an 'int' */
+        setivalue(L->top, va_arg(argp, int));
+        goto top2str;
+      }
+      case 'I': {  /* a 'lua_Integer' */
+        setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
+        goto top2str;
+      }
+      case 'f': {  /* a 'lua_Number' */
+        setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
+      top2str:  /* convert the top element to a string */
+        luaD_inctop(L);
         luaO_tostring(L, L->top - 1);
         break;
       }
-      case 'I': {
-        setivalue(L->top++, cast(lua_Integer, va_arg(argp, l_uacInt)));
-        luaO_tostring(L, L->top - 1);
-        break;
-      }
-      case 'f': {
-        setfltvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
-        luaO_tostring(L, L->top - 1);
-        break;
-      }
-      case 'p': {
+      case 'p': {  /* a pointer */
         char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
-        int l = sprintf(buff, "%p", va_arg(argp, void *));
+        void *p = va_arg(argp, void *);
+        int l = lua_pointer2str(buff, sizeof(buff), p);
         pushstr(L, buff, l);
         break;
       }
-      case 'U': {
+      case 'U': {  /* an 'int' as a UTF-8 sequence */
         char buff[UTF8BUFFSZ];
         int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
         pushstr(L, buff + UTF8BUFFSZ - l, l);
diff --git a/source/extern/lua/lobject.h b/source/extern/lua/lobject.h
index 9230b7a..2408861 100644
--- a/source/extern/lua/lobject.h
+++ b/source/extern/lua/lobject.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.h,v 2.111 2015/06/09 14:21:42 roberto Exp $
+** $Id: lobject.h,v 2.117.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Type definitions for Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -19,8 +19,8 @@
 /*
 ** Extra tags for non-values
 */
-#define LUA_TPROTO	LUA_NUMTAGS
-#define LUA_TDEADKEY	(LUA_NUMTAGS+1)
+#define LUA_TPROTO	LUA_NUMTAGS		/* function prototypes */
+#define LUA_TDEADKEY	(LUA_NUMTAGS+1)		/* removed keys in tables */
 
 /*
 ** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
@@ -88,22 +88,32 @@ struct GCObject {
 
 
 
-/*
-** Union of all Lua values
-*/
-typedef union Value Value;
-
-
-
 
 /*
 ** Tagged Values. This is the basic representation of values in Lua,
 ** an actual value plus a tag with its type.
 */
 
+/*
+** Union of all Lua values
+*/
+typedef union Value {
+  GCObject *gc;    /* collectable objects */
+  void *p;         /* light userdata */
+  int b;           /* booleans */
+  lua_CFunction f; /* light C functions */
+  lua_Integer i;   /* integer numbers */
+  lua_Number n;    /* float numbers */
+} Value;
+
+
 #define TValuefields	Value value_; int tt_
 
-typedef struct lua_TValue TValue;
+
+typedef struct lua_TValue {
+  TValuefields;
+} TValue;
+
 
 
 /* macro defining a nil value */
@@ -177,9 +187,9 @@ typedef struct lua_TValue TValue;
 /* Macros for internal tests */
 #define righttt(obj)		(ttype(obj) == gcvalue(obj)->tt)
 
-#define checkliveness(g,obj) \
+#define checkliveness(L,obj) \
 	lua_longassert(!iscollectable(obj) || \
-			(righttt(obj) && !isdead(g,gcvalue(obj))))
+		(righttt(obj) && (L == NULL || !isdead(G(L),gcvalue(obj)))))
 
 
 /* Macros to set values */
@@ -215,32 +225,32 @@ typedef struct lua_TValue TValue;
 #define setsvalue(L,obj,x) \
   { TValue *io = (obj); TString *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \
-    checkliveness(G(L),io); }
+    checkliveness(L,io); }
 
 #define setuvalue(L,obj,x) \
   { TValue *io = (obj); Udata *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TUSERDATA)); \
-    checkliveness(G(L),io); }
+    checkliveness(L,io); }
 
 #define setthvalue(L,obj,x) \
   { TValue *io = (obj); lua_State *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTHREAD)); \
-    checkliveness(G(L),io); }
+    checkliveness(L,io); }
 
 #define setclLvalue(L,obj,x) \
   { TValue *io = (obj); LClosure *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TLCL)); \
-    checkliveness(G(L),io); }
+    checkliveness(L,io); }
 
 #define setclCvalue(L,obj,x) \
   { TValue *io = (obj); CClosure *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TCCL)); \
-    checkliveness(G(L),io); }
+    checkliveness(L,io); }
 
 #define sethvalue(L,obj,x) \
   { TValue *io = (obj); Table *x_ = (x); \
     val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTABLE)); \
-    checkliveness(G(L),io); }
+    checkliveness(L,io); }
 
 #define setdeadvalue(obj)	settt_(obj, LUA_TDEADKEY)
 
@@ -248,7 +258,7 @@ typedef struct lua_TValue TValue;
 
 #define setobj(L,obj1,obj2) \
 	{ TValue *io1=(obj1); *io1 = *(obj2); \
-	  (void)L; checkliveness(G(L),io1); }
+	  (void)L; checkliveness(L,io1); }
 
 
 /*
@@ -264,12 +274,13 @@ typedef struct lua_TValue TValue;
 #define setptvalue2s	setptvalue
 /* from table to same table */
 #define setobjt2t	setobj
-/* to table */
-#define setobj2t	setobj
 /* to new object */
 #define setobj2n	setobj
 #define setsvalue2n	setsvalue
 
+/* to table (define it as an expression to be used in macros) */
+#define setobj2t(L,o1,o2)  ((void)L, *(o1)=*(o2), checkliveness(L,(o1)))
+
 
 
 
@@ -280,21 +291,6 @@ typedef struct lua_TValue TValue;
 */
 
 
-union Value {
-  GCObject *gc;    /* collectable objects */
-  void *p;         /* light userdata */
-  int b;           /* booleans */
-  lua_CFunction f; /* light C functions */
-  lua_Integer i;   /* integer numbers */
-  lua_Number n;    /* float numbers */
-};
-
-
-struct lua_TValue {
-  TValuefields;
-};
-
-
 typedef TValue *StkId;  /* index to stack elements */
 
 
@@ -329,9 +325,9 @@ typedef union UTString {
 ** Get the actual string (array of bytes) from a 'TString'.
 ** (Access to 'extra' ensures that value is really a 'TString'.)
 */
-#define getaddrstr(ts)	(cast(char *, (ts)) + sizeof(UTString))
 #define getstr(ts)  \
-  check_exp(sizeof((ts)->extra), cast(const char*, getaddrstr(ts)))
+  check_exp(sizeof((ts)->extra), cast(char *, (ts)) + sizeof(UTString))
+
 
 /* get the actual string (array of bytes) from a Lua value */
 #define svalue(o)       getstr(tsvalue(o))
@@ -375,13 +371,13 @@ typedef union UUdata {
 #define setuservalue(L,u,o) \
 	{ const TValue *io=(o); Udata *iu = (u); \
 	  iu->user_ = io->value_; iu->ttuv_ = rttype(io); \
-	  checkliveness(G(L),io); }
+	  checkliveness(L,io); }
 
 
 #define getuservalue(L,u,o) \
 	{ TValue *io=(o); const Udata *iu = (u); \
 	  io->value_ = iu->user_; settt_(io, iu->ttuv_); \
-	  checkliveness(G(L),io); }
+	  checkliveness(L,io); }
 
 
 /*
@@ -419,8 +415,8 @@ typedef struct Proto {
   int sizelineinfo;
   int sizep;  /* size of 'p' */
   int sizelocvars;
-  int linedefined;
-  int lastlinedefined;
+  int linedefined;  /* debug information  */
+  int lastlinedefined;  /* debug information  */
   TValue *k;  /* constants used by the function */
   Instruction *code;  /* opcodes */
   struct Proto **p;  /* functions defined inside the function */
@@ -489,7 +485,7 @@ typedef union TKey {
 #define setnodekey(L,key,obj) \
 	{ TKey *k_=(key); const TValue *io_=(obj); \
 	  k_->nk.value_ = io_->value_; k_->nk.tt_ = io_->tt_; \
-	  (void)L; checkliveness(G(L),io_); }
+	  (void)L; checkliveness(L,io_); }
 
 
 typedef struct Node {
diff --git a/source/extern/lua/lopcodes.c b/source/extern/lua/lopcodes.c
index a1cbef8..5ca3eb2 100644
--- a/source/extern/lua/lopcodes.c
+++ b/source/extern/lua/lopcodes.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.c,v 1.55 2015/01/05 13:48:33 roberto Exp $
+** $Id: lopcodes.c,v 1.55.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/lopcodes.h b/source/extern/lua/lopcodes.h
index 864b8e4..6feaa1c 100644
--- a/source/extern/lua/lopcodes.h
+++ b/source/extern/lua/lopcodes.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.h,v 1.148 2014/10/25 11:50:46 roberto Exp $
+** $Id: lopcodes.h,v 1.149.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -139,7 +139,9 @@ enum OpMode {iABC, iABx, iAsBx, iAx};  /* basic instruction format */
 /* gets the index of the constant */
 #define INDEXK(r)	((int)(r) & ~BITRK)
 
+#if !defined(MAXINDEXRK)  /* (for debugging only) */
 #define MAXINDEXRK	(BITRK - 1)
+#endif
 
 /* code a constant index as a RK value */
 #define RKASK(x)	((x) | BITRK)
diff --git a/source/extern/lua/loslib.c b/source/extern/lua/loslib.c
index cb8a3c3..de590c6 100644
--- a/source/extern/lua/loslib.c
+++ b/source/extern/lua/loslib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: loslib.c,v 1.57 2015/04/10 17:41:04 roberto Exp $
+** $Id: loslib.c,v 1.65.1.1 2017/04/19 17:29:57 roberto Exp $
 ** Standard Operating System library
 ** See Copyright Notice in lua.h
 */
@@ -24,18 +24,29 @@
 
 /*
 ** {==================================================================
-** list of valid conversion specifiers for the 'strftime' function
+** List of valid conversion specifiers for the 'strftime' function;
+** options are grouped by length; group of length 2 start with '||'.
 ** ===================================================================
 */
 #if !defined(LUA_STRFTIMEOPTIONS)	/* { */
 
-#if defined(LUA_USE_C89)
-#define LUA_STRFTIMEOPTIONS	{ "aAbBcdHIjmMpSUwWxXyYz%", "" }
+/* options for ANSI C 89 (only 1-char options) */
+#define L_STRFTIMEC89		"aAbBcdHIjmMpSUwWxXyYZ%"
+
+/* options for ISO C 99 and POSIX */
+#define L_STRFTIMEC99 "aAbBcCdDeFgGhHIjmMnprRStTuUVwWxXyYzZ%" \
+    "||" "EcECExEXEyEY" "OdOeOHOIOmOMOSOuOUOVOwOWOy"  /* two-char options */
+
+/* options for Windows */
+#define L_STRFTIMEWIN "aAbBcdHIjmMpSUwWxXyYzZ%" \
+    "||" "#c#x#d#H#I#j#m#M#S#U#w#W#y#Y"  /* two-char options */
+
+#if defined(LUA_USE_WINDOWS)
+#define LUA_STRFTIMEOPTIONS	L_STRFTIMEWIN
+#elif defined(LUA_USE_C89)
+#define LUA_STRFTIMEOPTIONS	L_STRFTIMEC89
 #else  /* C99 specification */
-#define LUA_STRFTIMEOPTIONS \
-	{ "aAbBcCdDeFgGhHIjmMnprRStTuUVwWxXyYzZ%", "", \
-	  "E", "cCxXyY",  \
-	  "O", "deHImMSuUVwWy" }
+#define LUA_STRFTIMEOPTIONS	L_STRFTIMEC99
 #endif
 
 #endif					/* } */
@@ -54,7 +65,12 @@
 */
 #define l_timet			lua_Integer
 #define l_pushtime(L,t)		lua_pushinteger(L,(lua_Integer)(t))
-#define l_checktime(L,a)	((time_t)luaL_checkinteger(L,a))
+
+static time_t l_checktime (lua_State *L, int arg) {
+  lua_Integer t = luaL_checkinteger(L, arg);
+  luaL_argcheck(L, (time_t)t == t, arg, "time out-of-bounds");
+  return (time_t)t;
+}
 
 #endif				/* } */
 
@@ -190,6 +206,23 @@ static void setboolfield (lua_State *L, const char *key, int value) {
   lua_setfield(L, -2, key);
 }
 
+
+/*
+** Set all fields from structure 'tm' in the table on top of the stack
+*/
+static void setallfields (lua_State *L, struct tm *stm) {
+  setfield(L, "sec", stm->tm_sec);
+  setfield(L, "min", stm->tm_min);
+  setfield(L, "hour", stm->tm_hour);
+  setfield(L, "day", stm->tm_mday);
+  setfield(L, "month", stm->tm_mon + 1);
+  setfield(L, "year", stm->tm_year + 1900);
+  setfield(L, "wday", stm->tm_wday + 1);
+  setfield(L, "yday", stm->tm_yday + 1);
+  setboolfield(L, "isdst", stm->tm_isdst);
+}
+
+
 static int getboolfield (lua_State *L, const char *key) {
   int res;
   res = (lua_getfield(L, -1, key) == LUA_TNIL) ? -1 : lua_toboolean(L, -1);
@@ -198,36 +231,43 @@ static int getboolfield (lua_State *L, const char *key) {
 }
 
 
-static int getfield (lua_State *L, const char *key, int d) {
-  int res, isnum;
-  lua_getfield(L, -1, key);
-  res = (int)lua_tointegerx(L, -1, &isnum);
-  if (!isnum) {
-    if (d < 0)
+/* maximum value for date fields (to avoid arithmetic overflows with 'int') */
+#if !defined(L_MAXDATEFIELD)
+#define L_MAXDATEFIELD	(INT_MAX / 2)
+#endif
+
+static int getfield (lua_State *L, const char *key, int d, int delta) {
+  int isnum;
+  int t = lua_getfield(L, -1, key);  /* get field and its type */
+  lua_Integer res = lua_tointegerx(L, -1, &isnum);
+  if (!isnum) {  /* field is not an integer? */
+    if (t != LUA_TNIL)  /* some other value? */
+      return luaL_error(L, "field '%s' is not an integer", key);
+    else if (d < 0)  /* absent field; no default? */
       return luaL_error(L, "field '%s' missing in date table", key);
     res = d;
   }
+  else {
+    if (!(-L_MAXDATEFIELD <= res && res <= L_MAXDATEFIELD))
+      return luaL_error(L, "field '%s' is out-of-bound", key);
+    res -= delta;
+  }
   lua_pop(L, 1);
-  return res;
+  return (int)res;
 }
 
 
-static const char *checkoption (lua_State *L, const char *conv, char *buff) {
-  static const char *const options[] = LUA_STRFTIMEOPTIONS;
-  unsigned int i;
-  for (i = 0; i < sizeof(options)/sizeof(options[0]); i += 2) {
-    if (*conv != '\0' && strchr(options[i], *conv) != NULL) {
-      buff[1] = *conv;
-      if (*options[i + 1] == '\0') {  /* one-char conversion specifier? */
-        buff[2] = '\0';  /* end buffer */
-        return conv + 1;
-      }
-      else if (*(conv + 1) != '\0' &&
-               strchr(options[i + 1], *(conv + 1)) != NULL) {
-        buff[2] = *(conv + 1);  /* valid two-char conversion specifier */
-        buff[3] = '\0';  /* end buffer */
-        return conv + 2;
-      }
+static const char *checkoption (lua_State *L, const char *conv,
+                                ptrdiff_t convlen, char *buff) {
+  const char *option = LUA_STRFTIMEOPTIONS;
+  int oplen = 1;  /* length of options being checked */
+  for (; *option != '\0' && oplen <= convlen; option += oplen) {
+    if (*option == '|')  /* next block? */
+      oplen++;  /* will check options with next length (+1) */
+    else if (memcmp(conv, option, oplen) == 0) {  /* match? */
+      memcpy(buff, conv, oplen);  /* copy valid option to buffer */
+      buff[oplen] = '\0';
+      return conv + oplen;  /* return next item */
     }
   }
   luaL_argerror(L, 1,
@@ -236,9 +276,15 @@ static const char *checkoption (lua_State *L, const char *conv, char *buff) {
 }
 
 
+/* maximum size for an individual 'strftime' item */
+#define SIZETIMEFMT	250
+
+
 static int os_date (lua_State *L) {
-  const char *s = luaL_optstring(L, 1, "%c");
+  size_t slen;
+  const char *s = luaL_optlstring(L, 1, "%c", &slen);
   time_t t = luaL_opt(L, l_checktime, 2, time(NULL));
+  const char *se = s + slen;  /* 's' end */
   struct tm tmr, *stm;
   if (*s == '!') {  /* UTC? */
     stm = l_gmtime(&t, &tmr);
@@ -247,33 +293,27 @@ static int os_date (lua_State *L) {
   else
     stm = l_localtime(&t, &tmr);
   if (stm == NULL)  /* invalid date? */
-    lua_pushnil(L);
-  else if (strcmp(s, "*t") == 0) {
+    return luaL_error(L,
+                 "time result cannot be represented in this installation");
+  if (strcmp(s, "*t") == 0) {
     lua_createtable(L, 0, 9);  /* 9 = number of fields */
-    setfield(L, "sec", stm->tm_sec);
-    setfield(L, "min", stm->tm_min);
-    setfield(L, "hour", stm->tm_hour);
-    setfield(L, "day", stm->tm_mday);
-    setfield(L, "month", stm->tm_mon+1);
-    setfield(L, "year", stm->tm_year+1900);
-    setfield(L, "wday", stm->tm_wday+1);
-    setfield(L, "yday", stm->tm_yday+1);
-    setboolfield(L, "isdst", stm->tm_isdst);
+    setallfields(L, stm);
   }
   else {
-    char cc[4];
+    char cc[4];  /* buffer for individual conversion specifiers */
     luaL_Buffer b;
     cc[0] = '%';
     luaL_buffinit(L, &b);
-    while (*s) {
-      if (*s != '%')  /* no conversion specifier? */
+    while (s < se) {
+      if (*s != '%')  /* not a conversion specifier? */
         luaL_addchar(&b, *s++);
       else {
         size_t reslen;
-        char buff[200];  /* should be big enough for any conversion result */
-        s = checkoption(L, s + 1, cc);
-        reslen = strftime(buff, sizeof(buff), cc, stm);
-        luaL_addlstring(&b, buff, reslen);
+        char *buff = luaL_prepbuffsize(&b, SIZETIMEFMT);
+        s++;  /* skip '%' */
+        s = checkoption(L, s, se - s, cc + 1);  /* copy specifier to 'cc' */
+        reslen = strftime(buff, SIZETIMEFMT, cc, stm);
+        luaL_addsize(&b, reslen);
       }
     }
     luaL_pushresult(&b);
@@ -290,21 +330,20 @@ static int os_time (lua_State *L) {
     struct tm ts;
     luaL_checktype(L, 1, LUA_TTABLE);
     lua_settop(L, 1);  /* make sure table is at the top */
-    ts.tm_sec = getfield(L, "sec", 0);
-    ts.tm_min = getfield(L, "min", 0);
-    ts.tm_hour = getfield(L, "hour", 12);
-    ts.tm_mday = getfield(L, "day", -1);
-    ts.tm_mon = getfield(L, "month", -1) - 1;
-    ts.tm_year = getfield(L, "year", -1) - 1900;
+    ts.tm_sec = getfield(L, "sec", 0, 0);
+    ts.tm_min = getfield(L, "min", 0, 0);
+    ts.tm_hour = getfield(L, "hour", 12, 0);
+    ts.tm_mday = getfield(L, "day", -1, 0);
+    ts.tm_mon = getfield(L, "month", -1, 1);
+    ts.tm_year = getfield(L, "year", -1, 1900);
     ts.tm_isdst = getboolfield(L, "isdst");
     t = mktime(&ts);
+    setallfields(L, &ts);  /* update fields with normalized values */
   }
-  if (t != (time_t)(l_timet)t)
-    luaL_error(L, "time result cannot be represented in this Lua installation");
-  else if (t == (time_t)(-1))
-    lua_pushnil(L);
-  else
-    l_pushtime(L, t);
+  if (t != (time_t)(l_timet)t || t == (time_t)(-1))
+    return luaL_error(L,
+                  "time result cannot be represented in this installation");
+  l_pushtime(L, t);
   return 1;
 }
 
diff --git a/source/extern/lua/lparser.c b/source/extern/lua/lparser.c
index 9a54dfc..2f41e00 100644
--- a/source/extern/lua/lparser.c
+++ b/source/extern/lua/lparser.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.c,v 2.147 2014/12/27 20:31:43 roberto Exp $
+** $Id: lparser.c,v 2.155.1.2 2017/04/29 18:11:40 roberto Exp $
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
@@ -164,7 +164,8 @@ static int registerlocalvar (LexState *ls, TString *varname) {
   int oldsize = f->sizelocvars;
   luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
                   LocVar, SHRT_MAX, "local variables");
-  while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL;
+  while (oldsize < f->sizelocvars)
+    f->locvars[oldsize++].varname = NULL;
   f->locvars[fs->nlocvars].varname = varname;
   luaC_objbarrier(ls->L, f, varname);
   return fs->nlocvars++;
@@ -230,7 +231,8 @@ static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
   checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues");
   luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues,
                   Upvaldesc, MAXUPVAL, "upvalues");
-  while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL;
+  while (oldsize < f->sizeupvalues)
+    f->upvalues[oldsize++].name = NULL;
   f->upvalues[fs->nups].instack = (v->k == VLOCAL);
   f->upvalues[fs->nups].idx = cast_byte(v->u.info);
   f->upvalues[fs->nups].name = name;
@@ -255,7 +257,8 @@ static int searchvar (FuncState *fs, TString *n) {
 */
 static void markupval (FuncState *fs, int level) {
   BlockCnt *bl = fs->bl;
-  while (bl->nactvar > level) bl = bl->previous;
+  while (bl->nactvar > level)
+    bl = bl->previous;
   bl->upval = 1;
 }
 
@@ -264,27 +267,26 @@ static void markupval (FuncState *fs, int level) {
   Find variable with given name 'n'. If it is an upvalue, add this
   upvalue into all intermediate functions.
 */
-static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
+static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
   if (fs == NULL)  /* no more levels? */
-    return VVOID;  /* default is global */
+    init_exp(var, VVOID, 0);  /* default is global */
   else {
     int v = searchvar(fs, n);  /* look up locals at current level */
     if (v >= 0) {  /* found? */
       init_exp(var, VLOCAL, v);  /* variable is local */
       if (!base)
         markupval(fs, v);  /* local will be used as an upval */
-      return VLOCAL;
     }
     else {  /* not found as local at current level; try upvalues */
       int idx = searchupvalue(fs, n);  /* try existing upvalues */
       if (idx < 0) {  /* not found? */
-        if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */
-          return VVOID;  /* not found; is a global */
+        singlevaraux(fs->prev, n, var, 0);  /* try upper levels */
+        if (var->k == VVOID)  /* not found? */
+          return;  /* it is a global */
         /* else was LOCAL or UPVAL */
         idx  = newupvalue(fs, n, var);  /* will be a new upvalue */
       }
-      init_exp(var, VUPVAL, idx);
-      return VUPVAL;
+      init_exp(var, VUPVAL, idx);  /* new or old upvalue */
     }
   }
 }
@@ -293,10 +295,11 @@ static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
 static void singlevar (LexState *ls, expdesc *var) {
   TString *varname = str_checkname(ls);
   FuncState *fs = ls->fs;
-  if (singlevaraux(fs, varname, var, 1) == VVOID) {  /* global name? */
+  singlevaraux(fs, varname, var, 1);
+  if (var->k == VVOID) {  /* global name? */
     expdesc key;
     singlevaraux(fs, ls->envn, var, 1);  /* get environment variable */
-    lua_assert(var->k == VLOCAL || var->k == VUPVAL);
+    lua_assert(var->k != VVOID);  /* this one must exist */
     codestring(ls, &key, varname);  /* key is variable name */
     luaK_indexed(fs, var, &key);  /* env[varname] */
   }
@@ -320,6 +323,8 @@ static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
       luaK_nil(fs, reg, extra);
     }
   }
+  if (nexps > nvars)
+    ls->fs->freereg -= nexps - nvars;  /* remove extra values */
 }
 
 
@@ -499,7 +504,8 @@ static Proto *addprototype (LexState *ls) {
   if (fs->np >= f->sizep) {
     int oldsize = f->sizep;
     luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions");
-    while (oldsize < f->sizep) f->p[oldsize++] = NULL;
+    while (oldsize < f->sizep)
+      f->p[oldsize++] = NULL;
   }
   f->p[fs->np++] = clp = luaF_newproto(L);
   luaC_objbarrier(L, f, clp);
@@ -538,6 +544,7 @@ static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
   fs->bl = NULL;
   f = fs->f;
   f->source = ls->source;
+  luaC_objbarrier(ls->L, f, f->source);
   f->maxstacksize = 2;  /* registers 0/1 are always valid */
   enterblock(fs, bl, 0);
 }
@@ -760,7 +767,7 @@ static void parlist (LexState *ls) {
         }
         case TK_DOTS: {  /* param -> '...' */
           luaX_next(ls);
-          f->is_vararg = 1;
+          f->is_vararg = 1;  /* declared vararg */
           break;
         }
         default: luaX_syntaxerror(ls, "<name> or '...' expected");
@@ -1155,11 +1162,8 @@ static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
     int nexps;
     checknext(ls, '=');
     nexps = explist(ls, &e);
-    if (nexps != nvars) {
+    if (nexps != nvars)
       adjust_assign(ls, nvars, nexps, &e);
-      if (nexps > nvars)
-        ls->fs->freereg -= nexps - nvars;  /* remove extra values */
-    }
     else {
       luaK_setoneret(ls->fs, &e);  /* close last expression */
       luaK_storevar(ls->fs, &lh->v, &e);
@@ -1225,7 +1229,7 @@ static void labelstat (LexState *ls, TString *label, int line) {
   checkrepeated(fs, ll, label);  /* check for repeated labels */
   checknext(ls, TK_DBCOLON);  /* skip double colon */
   /* create new entry for this label */
-  l = newlabelentry(ls, ll, label, line, fs->pc);
+  l = newlabelentry(ls, ll, label, line, luaK_getlabel(fs));
   skipnoopstat(ls);  /* skip other no-op statements */
   if (block_follow(ls, 0)) {  /* label is last no-op statement in the block? */
     /* assume that locals are already out of scope */
@@ -1389,7 +1393,7 @@ static void test_then_block (LexState *ls, int *escapelist) {
     luaK_goiffalse(ls->fs, &v);  /* will jump to label if condition is true */
     enterblock(fs, &bl, 0);  /* must enter block before 'goto' */
     gotostat(ls, v.t);  /* handle goto/break */
-    skipnoopstat(ls);  /* skip other no-op statements */
+    while (testnext(ls, ';')) {}  /* skip colons */
     if (block_follow(ls, 0)) {  /* 'goto' is the entire block? */
       leaveblock(fs);
       return;  /* and that is it */
@@ -1493,7 +1497,7 @@ static void exprstat (LexState *ls) {
   }
   else {  /* stat -> func */
     check_condition(ls, v.v.k == VCALL, "syntax error");
-    SETARG_C(getcode(fs, &v.v), 1);  /* call statement uses no results */
+    SETARG_C(getinstruction(fs, &v.v), 1);  /* call statement uses no results */
   }
 }
 
@@ -1510,8 +1514,8 @@ static void retstat (LexState *ls) {
     if (hasmultret(e.k)) {
       luaK_setmultret(fs, &e);
       if (e.k == VCALL && nret == 1) {  /* tail call? */
-        SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
-        lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
+        SET_OPCODE(getinstruction(fs,&e), OP_TAILCALL);
+        lua_assert(GETARG_A(getinstruction(fs,&e)) == fs->nactvar);
       }
       first = fs->nactvar;
       nret = LUA_MULTRET;  /* return all values */
@@ -1610,9 +1614,10 @@ static void mainfunc (LexState *ls, FuncState *fs) {
   BlockCnt bl;
   expdesc v;
   open_func(ls, fs, &bl);
-  fs->f->is_vararg = 1;  /* main function is always vararg */
+  fs->f->is_vararg = 1;  /* main function is always declared vararg */
   init_exp(&v, VLOCAL, 0);  /* create and... */
   newupvalue(fs, ls->envn, &v);  /* ...set environment upvalue */
+  luaC_objbarrier(ls->L, fs->f, ls->envn);
   luaX_next(ls);  /* read first token */
   statlist(ls);  /* parse main body */
   check(ls, TK_EOS);
@@ -1626,11 +1631,12 @@ LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
   FuncState funcstate;
   LClosure *cl = luaF_newLclosure(L, 1);  /* create main closure */
   setclLvalue(L, L->top, cl);  /* anchor it (to avoid being collected) */
-  incr_top(L);
+  luaD_inctop(L);
   lexstate.h = luaH_new(L);  /* create table for scanner */
   sethvalue(L, L->top, lexstate.h);  /* anchor it */
-  incr_top(L);
+  luaD_inctop(L);
   funcstate.f = cl->p = luaF_newproto(L);
+  luaC_objbarrier(L, cl, cl->p);
   funcstate.f->source = luaS_new(L, name);  /* create and anchor TString */
   lua_assert(iswhite(funcstate.f));  /* do not need barrier here */
   lexstate.buff = buff;
diff --git a/source/extern/lua/lparser.h b/source/extern/lua/lparser.h
index 62c50ca..f45b23c 100644
--- a/source/extern/lua/lparser.h
+++ b/source/extern/lua/lparser.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.h,v 1.74 2014/10/25 11:50:46 roberto Exp $
+** $Id: lparser.h,v 1.76.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
@@ -13,25 +13,38 @@
 
 
 /*
-** Expression descriptor
+** Expression and variable descriptor.
+** Code generation for variables and expressions can be delayed to allow
+** optimizations; An 'expdesc' structure describes a potentially-delayed
+** variable/expression. It has a description of its "main" value plus a
+** list of conditional jumps that can also produce its value (generated
+** by short-circuit operators 'and'/'or').
 */
 
+/* kinds of variables/expressions */
 typedef enum {
-  VVOID,	/* no value */
-  VNIL,
-  VTRUE,
-  VFALSE,
-  VK,		/* info = index of constant in 'k' */
-  VKFLT,	/* nval = numerical float value */
-  VKINT,	/* nval = numerical integer value */
-  VNONRELOC,	/* info = result register */
-  VLOCAL,	/* info = local register */
-  VUPVAL,       /* info = index of upvalue in 'upvalues' */
-  VINDEXED,	/* t = table register/upvalue; idx = index R/K */
-  VJMP,		/* info = instruction pc */
-  VRELOCABLE,	/* info = instruction pc */
-  VCALL,	/* info = instruction pc */
-  VVARARG	/* info = instruction pc */
+  VVOID,  /* when 'expdesc' describes the last expression a list,
+             this kind means an empty list (so, no expression) */
+  VNIL,  /* constant nil */
+  VTRUE,  /* constant true */
+  VFALSE,  /* constant false */
+  VK,  /* constant in 'k'; info = index of constant in 'k' */
+  VKFLT,  /* floating constant; nval = numerical float value */
+  VKINT,  /* integer constant; nval = numerical integer value */
+  VNONRELOC,  /* expression has its value in a fixed register;
+                 info = result register */
+  VLOCAL,  /* local variable; info = local register */
+  VUPVAL,  /* upvalue variable; info = index of upvalue in 'upvalues' */
+  VINDEXED,  /* indexed variable;
+                ind.vt = whether 't' is register or upvalue;
+                ind.t = table register or upvalue;
+                ind.idx = key's R/K index */
+  VJMP,  /* expression is a test/comparison;
+            info = pc of corresponding jump instruction */
+  VRELOCABLE,  /* expression can put result in any register;
+                  info = instruction pc */
+  VCALL,  /* expression is a function call; info = instruction pc */
+  VVARARG  /* vararg expression; info = instruction pc */
 } expkind;
 
 
@@ -41,14 +54,14 @@ typedef enum {
 typedef struct expdesc {
   expkind k;
   union {
+    lua_Integer ival;    /* for VKINT */
+    lua_Number nval;  /* for VKFLT */
+    int info;  /* for generic use */
     struct {  /* for indexed variables (VINDEXED) */
       short idx;  /* index (R/K) */
       lu_byte t;  /* table (register or upvalue) */
       lu_byte vt;  /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */
     } ind;
-    int info;  /* for generic use */
-    lua_Number nval;  /* for VKFLT */
-    lua_Integer ival;    /* for VKINT */
   } u;
   int t;  /* patch list of 'exit when true' */
   int f;  /* patch list of 'exit when false' */
diff --git a/source/extern/lua/lprefix.h b/source/extern/lua/lprefix.h
index 02daa83..9a749a3 100644
--- a/source/extern/lua/lprefix.h
+++ b/source/extern/lua/lprefix.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lprefix.h,v 1.2 2014/12/29 16:54:13 roberto Exp $
+** $Id: lprefix.h,v 1.2.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Definitions for Lua code that must come before any other header file
 ** See Copyright Notice in lua.h
 */
diff --git a/source/extern/lua/lstate.c b/source/extern/lua/lstate.c
index 12e51d2..c1a7664 100644
--- a/source/extern/lua/lstate.c
+++ b/source/extern/lua/lstate.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.c,v 2.128 2015/03/04 13:31:21 roberto Exp $
+** $Id: lstate.c,v 2.133.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -76,7 +76,7 @@ typedef struct LG {
 */
 #define addbuff(b,p,e) \
   { size_t t = cast(size_t, e); \
-    memcpy(buff + p, &t, sizeof(t)); p += sizeof(t); }
+    memcpy(b + p, &t, sizeof(t)); p += sizeof(t); }
 
 static unsigned int makeseed (lua_State *L) {
   char buff[4 * sizeof(size_t)];
@@ -93,10 +93,14 @@ static unsigned int makeseed (lua_State *L) {
 
 /*
 ** set GCdebt to a new value keeping the value (totalbytes + GCdebt)
-** invariant
+** invariant (and avoiding underflows in 'totalbytes')
 */
 void luaE_setdebt (global_State *g, l_mem debt) {
-  g->totalbytes -= (debt - g->GCdebt);
+  l_mem tb = gettotalbytes(g);
+  lua_assert(tb > 0);
+  if (debt < tb - MAX_LMEM)
+    debt = tb - MAX_LMEM;  /* will make 'totalbytes == MAX_LMEM' */
+  g->totalbytes = tb - debt;
   g->GCdebt = debt;
 }
 
@@ -107,6 +111,7 @@ CallInfo *luaE_extendCI (lua_State *L) {
   L->ci->next = ci;
   ci->previous = L->ci;
   ci->next = NULL;
+  L->nci++;
   return ci;
 }
 
@@ -121,6 +126,7 @@ void luaE_freeCI (lua_State *L) {
   while ((ci = next) != NULL) {
     next = ci->next;
     luaM_free(L, ci);
+    L->nci--;
   }
 }
 
@@ -130,13 +136,14 @@ void luaE_freeCI (lua_State *L) {
 */
 void luaE_shrinkCI (lua_State *L) {
   CallInfo *ci = L->ci;
-  while (ci->next != NULL) {  /* while there is 'next' */
-    CallInfo *next2 = ci->next->next;  /* next's next */
-    if (next2 == NULL) break;
-    luaM_free(L, ci->next);  /* remove next */
+  CallInfo *next2;  /* next's next */
+  /* while there are two nexts */
+  while (ci->next != NULL && (next2 = ci->next->next) != NULL) {
+    luaM_free(L, ci->next);  /* free next */
+    L->nci--;
     ci->next = next2;  /* remove 'next' from the list */
     next2->previous = ci;
-    ci = next2;
+    ci = next2;  /* keep next's next */
   }
 }
 
@@ -166,6 +173,7 @@ static void freestack (lua_State *L) {
     return;  /* stack not completely built yet */
   L->ci = &L->base_ci;  /* free the entire 'ci' list */
   luaE_freeCI(L);
+  lua_assert(L->nci == 0);
   luaM_freearray(L, L->stack, L->stacksize);  /* free stack array */
 }
 
@@ -214,6 +222,7 @@ static void preinit_thread (lua_State *L, global_State *g) {
   G(L) = g;
   L->stack = NULL;
   L->ci = NULL;
+  L->nci = 0;
   L->stacksize = 0;
   L->twups = L;  /* thread has no upvalues */
   L->errorJmp = NULL;
@@ -237,7 +246,6 @@ static void close_state (lua_State *L) {
   if (g->version)  /* closing a fully built state? */
     luai_userstateclose(L);
   luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
-  luaZ_freebuffer(L, &g->buff);
   freestack(L);
   lua_assert(gettotalbytes(g) == sizeof(LG));
   (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0);  /* free main block */
@@ -306,7 +314,6 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   g->strt.size = g->strt.nuse = 0;
   g->strt.hash = NULL;
   setnilvalue(&g->l_registry);
-  luaZ_initbuffer(L, &g->buff);
   g->panic = NULL;
   g->version = NULL;
   g->gcstate = GCSpause;
diff --git a/source/extern/lua/lstate.h b/source/extern/lua/lstate.h
index eefc217..56b3741 100644
--- a/source/extern/lua/lstate.h
+++ b/source/extern/lua/lstate.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 2.122 2015/06/01 16:34:37 roberto Exp $
+** $Id: lstate.h,v 2.133.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -23,9 +23,27 @@
 **
 ** 'allgc': all objects not marked for finalization;
 ** 'finobj': all objects marked for finalization;
-** 'tobefnz': all objects ready to be finalized; 
+** 'tobefnz': all objects ready to be finalized;
 ** 'fixedgc': all objects that are not to be collected (currently
 ** only small strings, such as reserved words).
+**
+** Moreover, there is another set of lists that control gray objects.
+** These lists are linked by fields 'gclist'. (All objects that
+** can become gray have such a field. The field is not the same
+** in all objects, but it always has this name.)  Any gray object
+** must belong to one of these lists, and all objects in these lists
+** must be gray:
+**
+** 'gray': regular gray objects, still waiting to be visited.
+** 'grayagain': objects that must be revisited at the atomic phase.
+**   That includes
+**   - black objects got in a write barrier;
+**   - all kinds of weak tables during propagation phase;
+**   - all threads.
+** 'weak': tables with weak values to be cleared;
+** 'ephemeron': ephemeron tables with white->white entries;
+** 'allweak': tables with weak keys and/or weak values to be cleared.
+** The last three lists are used only during the atomic phase.
 
 */
 
@@ -33,6 +51,15 @@
 struct lua_longjmp;  /* defined in ldo.c */
 
 
+/*
+** Atomic type (relative to signals) to better ensure that 'lua_sethook'
+** is thread safe
+*/
+#if !defined(l_signalT)
+#include <signal.h>
+#define l_signalT	sig_atomic_t
+#endif
+
 
 /* extra stack space to handle TM calls and some other extras */
 #define EXTRA_STACK   5
@@ -57,7 +84,7 @@ typedef struct stringtable {
 ** Information about a call.
 ** When a thread yields, 'func' is adjusted to pretend that the
 ** top function has only the yielded values in its stack; in that
-** case, the actual 'func' value is saved in field 'extra'. 
+** case, the actual 'func' value is saved in field 'extra'.
 ** When a function calls another with a continuation, 'extra' keeps
 ** the function index so that, in case of errors, the continuation
 ** function can be called with the correct top.
@@ -79,7 +106,7 @@ typedef struct CallInfo {
   } u;
   ptrdiff_t extra;
   short nresults;  /* expected number of results from this function */
-  lu_byte callstatus;
+  unsigned short callstatus;
 } CallInfo;
 
 
@@ -89,12 +116,13 @@ typedef struct CallInfo {
 #define CIST_OAH	(1<<0)	/* original value of 'allowhook' */
 #define CIST_LUA	(1<<1)	/* call is running a Lua function */
 #define CIST_HOOKED	(1<<2)	/* call is running a debug hook */
-#define CIST_REENTRY	(1<<3)	/* call is running on same invocation of
-                                   luaV_execute of previous call */
+#define CIST_FRESH	(1<<3)	/* call is running on a fresh invocation
+                                   of luaV_execute */
 #define CIST_YPCALL	(1<<4)	/* call is a yieldable protected call */
 #define CIST_TAIL	(1<<5)	/* call was tail called */
 #define CIST_HOOKYIELD	(1<<6)	/* last hook called yielded */
 #define CIST_LEQ	(1<<7)  /* using __lt for __le */
+#define CIST_FIN	(1<<8)  /* call is running a finalizer */
 
 #define isLua(ci)	((ci)->callstatus & CIST_LUA)
 
@@ -109,7 +137,7 @@ typedef struct CallInfo {
 typedef struct global_State {
   lua_Alloc frealloc;  /* function to reallocate memory */
   void *ud;         /* auxiliary data to 'frealloc' */
-  lu_mem totalbytes;  /* number of bytes currently allocated - GCdebt */
+  l_mem totalbytes;  /* number of bytes currently allocated - GCdebt */
   l_mem GCdebt;  /* bytes allocated not yet compensated by the collector */
   lu_mem GCmemtrav;  /* memory traversed by the GC */
   lu_mem GCestimate;  /* an estimate of the non-garbage memory in use */
@@ -131,7 +159,6 @@ typedef struct global_State {
   GCObject *tobefnz;  /* list of userdata to be GC */
   GCObject *fixedgc;  /* list of objects not to be collected */
   struct lua_State *twups;  /* list of threads with open upvalues */
-  Mbuffer buff;  /* temporary buffer for string concatenation */
   unsigned int gcfinnum;  /* number of finalizers to call in each GC step */
   int gcpause;  /* size of pause between successive GCs */
   int gcstepmul;  /* GC 'granularity' */
@@ -141,7 +168,7 @@ typedef struct global_State {
   TString *memerrmsg;  /* memory-error message */
   TString *tmname[TM_N];  /* array with tag-method names */
   struct Table *mt[LUA_NUMTAGS];  /* metatables for basic types */
-  TString *strcache[STRCACHE_SIZE][1];  /* cache for strings in API */
+  TString *strcache[STRCACHE_N][STRCACHE_M];  /* cache for strings in API */
 } global_State;
 
 
@@ -150,6 +177,7 @@ typedef struct global_State {
 */
 struct lua_State {
   CommonHeader;
+  unsigned short nci;  /* number of items in 'ci' list */
   lu_byte status;
   StkId top;  /* first free slot in the stack */
   global_State *l_G;
@@ -162,14 +190,14 @@ struct lua_State {
   struct lua_State *twups;  /* list of threads with open upvalues */
   struct lua_longjmp *errorJmp;  /* current error recover point */
   CallInfo base_ci;  /* CallInfo for first level (C calling Lua) */
-  lua_Hook hook;
+  volatile lua_Hook hook;
   ptrdiff_t errfunc;  /* current error handling function (stack index) */
   int stacksize;
   int basehookcount;
   int hookcount;
   unsigned short nny;  /* number of non-yieldable calls in stack */
   unsigned short nCcalls;  /* number of nested C calls */
-  lu_byte hookmask;
+  l_signalT hookmask;
   lu_byte allowhook;
 };
 
@@ -212,7 +240,7 @@ union GCUnion {
 
 
 /* actual number of total bytes allocated */
-#define gettotalbytes(g)	((g)->totalbytes + (g)->GCdebt)
+#define gettotalbytes(g)	cast(lu_mem, (g)->totalbytes + (g)->GCdebt)
 
 LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt);
 LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
diff --git a/source/extern/lua/lstring.c b/source/extern/lua/lstring.c
index 5e0e3c4..6257f21 100644
--- a/source/extern/lua/lstring.c
+++ b/source/extern/lua/lstring.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.c,v 2.49 2015/06/01 16:34:37 roberto Exp $
+** $Id: lstring.c,v 2.56.1.1 2017/04/19 17:20:42 roberto Exp $
 ** String table (keeps all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -48,14 +48,23 @@ int luaS_eqlngstr (TString *a, TString *b) {
 
 unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
   unsigned int h = seed ^ cast(unsigned int, l);
-  size_t l1;
   size_t step = (l >> LUAI_HASHLIMIT) + 1;
-  for (l1 = l; l1 >= step; l1 -= step)
-    h = h ^ ((h<<5) + (h>>2) + cast_byte(str[l1 - 1]));
+  for (; l >= step; l -= step)
+    h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1]));
   return h;
 }
 
 
+unsigned int luaS_hashlongstr (TString *ts) {
+  lua_assert(ts->tt == LUA_TLNGSTR);
+  if (ts->extra == 0) {  /* no hash? */
+    ts->hash = luaS_hash(getstr(ts), ts->u.lnglen, ts->hash);
+    ts->extra = 1;  /* now it has its hash */
+  }
+  return ts->hash;
+}
+
+
 /*
 ** resizes the string table
 */
@@ -92,11 +101,12 @@ void luaS_resize (lua_State *L, int newsize) {
 ** a non-collectable string.)
 */
 void luaS_clearcache (global_State *g) {
-  int i;
-  for (i = 0; i < STRCACHE_SIZE; i++) {
-    if (iswhite(g->strcache[i][0]))  /* will entry be collected? */
-      g->strcache[i][0] = g->memerrmsg;  /* replace it with something fixed */
-  }
+  int i, j;
+  for (i = 0; i < STRCACHE_N; i++)
+    for (j = 0; j < STRCACHE_M; j++) {
+    if (iswhite(g->strcache[i][j]))  /* will entry be collected? */
+      g->strcache[i][j] = g->memerrmsg;  /* replace it with something fixed */
+    }
 }
 
 
@@ -105,13 +115,14 @@ void luaS_clearcache (global_State *g) {
 */
 void luaS_init (lua_State *L) {
   global_State *g = G(L);
-  int i;
+  int i, j;
   luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */
   /* pre-create memory-error message */
   g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
   luaC_fix(L, obj2gco(g->memerrmsg));  /* it should never be collected */
-  for (i = 0; i < STRCACHE_SIZE; i++)  /* fill cache with valid strings */
-    g->strcache[i][0] = g->memerrmsg;
+  for (i = 0; i < STRCACHE_N; i++)  /* fill cache with valid strings */
+    for (j = 0; j < STRCACHE_M; j++)
+      g->strcache[i][j] = g->memerrmsg;
 }
 
 
@@ -119,8 +130,7 @@ void luaS_init (lua_State *L) {
 /*
 ** creates a new string object
 */
-static TString *createstrobj (lua_State *L, const char *str, size_t l,
-                              int tag, unsigned int h) {
+static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) {
   TString *ts;
   GCObject *o;
   size_t totalsize;  /* total size of TString object */
@@ -129,8 +139,14 @@ static TString *createstrobj (lua_State *L, const char *str, size_t l,
   ts = gco2ts(o);
   ts->hash = h;
   ts->extra = 0;
-  memcpy(getaddrstr(ts), str, l * sizeof(char));
-  getaddrstr(ts)[l] = '\0';  /* ending 0 */
+  getstr(ts)[l] = '\0';  /* ending 0 */
+  return ts;
+}
+
+
+TString *luaS_createlngstrobj (lua_State *L, size_t l) {
+  TString *ts = createstrobj(L, l, LUA_TLNGSTR, G(L)->seed);
+  ts->u.lnglen = l;
   return ts;
 }
 
@@ -153,6 +169,7 @@ static TString *internshrstr (lua_State *L, const char *str, size_t l) {
   global_State *g = G(L);
   unsigned int h = luaS_hash(str, l, g->seed);
   TString **list = &g->strt.hash[lmod(h, g->strt.size)];
+  lua_assert(str != NULL);  /* otherwise 'memcmp'/'memcpy' are undefined */
   for (ts = *list; ts != NULL; ts = ts->u.hnext) {
     if (l == ts->shrlen &&
         (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) {
@@ -166,7 +183,8 @@ static TString *internshrstr (lua_State *L, const char *str, size_t l) {
     luaS_resize(L, g->strt.size * 2);
     list = &g->strt.hash[lmod(h, g->strt.size)];  /* recompute with new size */
   }
-  ts = createstrobj(L, str, l, LUA_TSHRSTR, h);
+  ts = createstrobj(L, l, LUA_TSHRSTR, h);
+  memcpy(getstr(ts), str, l * sizeof(char));
   ts->shrlen = cast_byte(l);
   ts->u.hnext = *list;
   *list = ts;
@@ -183,10 +201,10 @@ TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
     return internshrstr(L, str, l);
   else {
     TString *ts;
-    if (l + 1 > (MAX_SIZE - sizeof(TString))/sizeof(char))
+    if (l >= (MAX_SIZE - sizeof(TString))/sizeof(char))
       luaM_toobig(L);
-    ts = createstrobj(L, str, l, LUA_TLNGSTR, G(L)->seed);
-    ts->u.lnglen = l;
+    ts = luaS_createlngstrobj(L, l);
+    memcpy(getstr(ts), str, l * sizeof(char));
     return ts;
   }
 }
@@ -199,15 +217,19 @@ TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
 ** check hits.
 */
 TString *luaS_new (lua_State *L, const char *str) {
-  unsigned int i = point2uint(str) % STRCACHE_SIZE;  /* hash */
+  unsigned int i = point2uint(str) % STRCACHE_N;  /* hash */
+  int j;
   TString **p = G(L)->strcache[i];
-  if (strcmp(str, getstr(p[0])) == 0)  /* hit? */
-    return p[0];  /* that it is */
-  else {  /* normal route */
-    TString *s = luaS_newlstr(L, str, strlen(str));
-    p[0] = s;
-    return s;
+  for (j = 0; j < STRCACHE_M; j++) {
+    if (strcmp(str, getstr(p[j])) == 0)  /* hit? */
+      return p[j];  /* that is it */
   }
+  /* normal route */
+  for (j = STRCACHE_M - 1; j > 0; j--)
+    p[j] = p[j - 1];  /* move out last element */
+  /* new element is first in the list */
+  p[0] = luaS_newlstr(L, str, strlen(str));
+  return p[0];
 }
 
 
diff --git a/source/extern/lua/lstring.h b/source/extern/lua/lstring.h
index e746f5f..d612abd 100644
--- a/source/extern/lua/lstring.h
+++ b/source/extern/lua/lstring.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.h,v 1.59 2015/03/25 13:42:19 roberto Exp $
+** $Id: lstring.h,v 1.61.1.1 2017/04/19 17:20:42 roberto Exp $
 ** String table (keep all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -34,6 +34,7 @@
 
 
 LUAI_FUNC unsigned int luaS_hash (const char *str, size_t l, unsigned int seed);
+LUAI_FUNC unsigned int luaS_hashlongstr (TString *ts);
 LUAI_FUNC int luaS_eqlngstr (TString *a, TString *b);
 LUAI_FUNC void luaS_resize (lua_State *L, int newsize);
 LUAI_FUNC void luaS_clearcache (global_State *g);
@@ -42,6 +43,7 @@ LUAI_FUNC void luaS_remove (lua_State *L, TString *ts);
 LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s);
 LUAI_FUNC TString *luaS_newlstr (lua_State *L, const char *str, size_t l);
 LUAI_FUNC TString *luaS_new (lua_State *L, const char *str);
+LUAI_FUNC TString *luaS_createlngstrobj (lua_State *L, size_t l);
 
 
 #endif
diff --git a/source/extern/lua/lstrlib.c b/source/extern/lua/lstrlib.c
index 19c350d..b4bed7e 100644
--- a/source/extern/lua/lstrlib.c
+++ b/source/extern/lua/lstrlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstrlib.c,v 1.229 2015/05/20 17:39:23 roberto Exp $
+** $Id: lstrlib.c,v 1.254.1.1 2017/04/19 17:29:57 roberto Exp $
 ** Standard library for string operations and pattern-matching
 ** See Copyright Notice in lua.h
 */
@@ -13,6 +13,7 @@
 #include <ctype.h>
 #include <float.h>
 #include <limits.h>
+#include <locale.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -26,7 +27,8 @@
 
 /*
 ** maximum number of captures that a pattern can do during
-** pattern-matching. This limit is arbitrary.
+** pattern-matching. This limit is arbitrary, but must fit in
+** an unsigned char.
 */
 #if !defined(LUA_MAXCAPTURES)
 #define LUA_MAXCAPTURES		32
@@ -41,8 +43,10 @@
 ** Some sizes are better limited to fit in 'int', but must also fit in
 ** 'size_t'. (We assume that 'lua_Integer' cannot be smaller than 'int'.)
 */
+#define MAX_SIZET	((size_t)(~(size_t)0))
+
 #define MAXSIZE  \
-	(sizeof(size_t) < sizeof(int) ? (~(size_t)0) : (size_t)(INT_MAX))
+	(sizeof(size_t) < sizeof(int) ? MAX_SIZET : (size_t)(INT_MAX))
 
 
 
@@ -208,12 +212,12 @@ static int str_dump (lua_State *L) {
 
 
 typedef struct MatchState {
-  int matchdepth;  /* control for recursive depth (to avoid C stack overflow) */
   const char *src_init;  /* init of source string */
   const char *src_end;  /* end ('\0') of source string */
   const char *p_end;  /* end ('\0') of pattern */
   lua_State *L;
-  int level;  /* total number of captures (finished or unfinished) */
+  int matchdepth;  /* control for recursive depth (to avoid C stack overflow) */
+  unsigned char level;  /* total number of captures (finished or unfinished) */
   struct {
     const char *init;
     ptrdiff_t len;
@@ -584,6 +588,22 @@ static int nospecials (const char *p, size_t l) {
 }
 
 
+static void prepstate (MatchState *ms, lua_State *L,
+                       const char *s, size_t ls, const char *p, size_t lp) {
+  ms->L = L;
+  ms->matchdepth = MAXCCALLS;
+  ms->src_init = s;
+  ms->src_end = s + ls;
+  ms->p_end = p + lp;
+}
+
+
+static void reprepstate (MatchState *ms) {
+  ms->level = 0;
+  lua_assert(ms->matchdepth == MAXCCALLS);
+}
+
+
 static int str_find_aux (lua_State *L, int find) {
   size_t ls, lp;
   const char *s = luaL_checklstring(L, 1, &ls);
@@ -611,15 +631,10 @@ static int str_find_aux (lua_State *L, int find) {
     if (anchor) {
       p++; lp--;  /* skip anchor character */
     }
-    ms.L = L;
-    ms.matchdepth = MAXCCALLS;
-    ms.src_init = s;
-    ms.src_end = s + ls;
-    ms.p_end = p + lp;
+    prepstate(&ms, L, s, ls, p, lp);
     do {
       const char *res;
-      ms.level = 0;
-      lua_assert(ms.matchdepth == MAXCCALLS);
+      reprepstate(&ms);
       if ((res=match(&ms, s1, p)) != NULL) {
         if (find) {
           lua_pushinteger(L, (s1 - s) + 1);  /* start */
@@ -646,29 +661,25 @@ static int str_match (lua_State *L) {
 }
 
 
+/* state for 'gmatch' */
+typedef struct GMatchState {
+  const char *src;  /* current position */
+  const char *p;  /* pattern */
+  const char *lastmatch;  /* end of last match */
+  MatchState ms;  /* match state */
+} GMatchState;
+
+
 static int gmatch_aux (lua_State *L) {
-  MatchState ms;
-  size_t ls, lp;
-  const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls);
-  const char *p = lua_tolstring(L, lua_upvalueindex(2), &lp);
+  GMatchState *gm = (GMatchState *)lua_touserdata(L, lua_upvalueindex(3));
   const char *src;
-  ms.L = L;
-  ms.matchdepth = MAXCCALLS;
-  ms.src_init = s;
-  ms.src_end = s+ls;
-  ms.p_end = p + lp;
-  for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3));
-       src <= ms.src_end;
-       src++) {
+  gm->ms.L = L;
+  for (src = gm->src; src <= gm->ms.src_end; src++) {
     const char *e;
-    ms.level = 0;
-    lua_assert(ms.matchdepth == MAXCCALLS);
-    if ((e = match(&ms, src, p)) != NULL) {
-      lua_Integer newstart = e-s;
-      if (e == src) newstart++;  /* empty match? go at least one position */
-      lua_pushinteger(L, newstart);
-      lua_replace(L, lua_upvalueindex(3));
-      return push_captures(&ms, src, e);
+    reprepstate(&gm->ms);
+    if ((e = match(&gm->ms, src, gm->p)) != NULL && e != gm->lastmatch) {
+      gm->src = gm->lastmatch = e;
+      return push_captures(&gm->ms, src, e);
     }
   }
   return 0;  /* not found */
@@ -676,10 +687,14 @@ static int gmatch_aux (lua_State *L) {
 
 
 static int gmatch (lua_State *L) {
-  luaL_checkstring(L, 1);
-  luaL_checkstring(L, 2);
-  lua_settop(L, 2);
-  lua_pushinteger(L, 0);
+  size_t ls, lp;
+  const char *s = luaL_checklstring(L, 1, &ls);
+  const char *p = luaL_checklstring(L, 2, &lp);
+  GMatchState *gm;
+  lua_settop(L, 2);  /* keep them on closure to avoid being collected */
+  gm = (GMatchState *)lua_newuserdata(L, sizeof(GMatchState));
+  prepstate(&gm->ms, L, s, ls, p, lp);
+  gm->src = s; gm->p = p; gm->lastmatch = NULL;
   lua_pushcclosure(L, gmatch_aux, 3);
   return 1;
 }
@@ -746,12 +761,13 @@ static void add_value (MatchState *ms, luaL_Buffer *b, const char *s,
 
 static int str_gsub (lua_State *L) {
   size_t srcl, lp;
-  const char *src = luaL_checklstring(L, 1, &srcl);
-  const char *p = luaL_checklstring(L, 2, &lp);
-  int tr = lua_type(L, 3);
-  lua_Integer max_s = luaL_optinteger(L, 4, srcl + 1);
+  const char *src = luaL_checklstring(L, 1, &srcl);  /* subject */
+  const char *p = luaL_checklstring(L, 2, &lp);  /* pattern */
+  const char *lastmatch = NULL;  /* end of last match */
+  int tr = lua_type(L, 3);  /* replacement type */
+  lua_Integer max_s = luaL_optinteger(L, 4, srcl + 1);  /* max replacements */
   int anchor = (*p == '^');
-  lua_Integer n = 0;
+  lua_Integer n = 0;  /* replacement count */
   MatchState ms;
   luaL_Buffer b;
   luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING ||
@@ -761,25 +777,18 @@ static int str_gsub (lua_State *L) {
   if (anchor) {
     p++; lp--;  /* skip anchor character */
   }
-  ms.L = L;
-  ms.matchdepth = MAXCCALLS;
-  ms.src_init = src;
-  ms.src_end = src+srcl;
-  ms.p_end = p + lp;
+  prepstate(&ms, L, src, srcl, p, lp);
   while (n < max_s) {
     const char *e;
-    ms.level = 0;
-    lua_assert(ms.matchdepth == MAXCCALLS);
-    e = match(&ms, src, p);
-    if (e) {
+    reprepstate(&ms);  /* (re)prepare state for new match */
+    if ((e = match(&ms, src, p)) != NULL && e != lastmatch) {  /* match? */
       n++;
-      add_value(&ms, &b, src, e, tr);
+      add_value(&ms, &b, src, e, tr);  /* add replacement to buffer */
+      src = lastmatch = e;
     }
-    if (e && e>src) /* non empty match? */
-      src = e;  /* skip it */
-    else if (src < ms.src_end)
+    else if (src < ms.src_end)  /* otherwise, skip one character */
       luaL_addchar(&b, *src++);
-    else break;
+    else break;  /* end of subject */
     if (anchor) break;
   }
   luaL_addlstring(&b, src, ms.src_end-src);
@@ -804,7 +813,6 @@ static int str_gsub (lua_State *L) {
 ** Hexadecimal floating-point formatter
 */
 
-#include <locale.h>
 #include <math.h>
 
 #define SIZELENMOD	(sizeof(LUA_NUMBER_FRMLEN)/sizeof(char))
@@ -830,13 +838,13 @@ static lua_Number adddigit (char *buff, int n, lua_Number x) {
 }
 
 
-static int num2straux (char *buff, lua_Number x) {
-  if (x != x || x == HUGE_VAL || x == -HUGE_VAL)  /* inf or NaN? */
-    return sprintf(buff, LUA_NUMBER_FMT, x);  /* equal to '%g' */
+static int num2straux (char *buff, int sz, lua_Number x) {
+  /* if 'inf' or 'NaN', format it like '%g' */
+  if (x != x || x == (lua_Number)HUGE_VAL || x == -(lua_Number)HUGE_VAL)
+    return l_sprintf(buff, sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)x);
   else if (x == 0) {  /* can be -0... */
-    sprintf(buff, LUA_NUMBER_FMT, x);
-    strcat(buff, "x0p+0");  /* reuses '0/-0' from 'sprintf'... */
-    return strlen(buff);
+    /* create "0" or "-0" followed by exponent */
+    return l_sprintf(buff, sz, LUA_NUMBER_FMT "x0p+0", (LUAI_UACNUMBER)x);
   }
   else {
     int e;
@@ -855,22 +863,23 @@ static int num2straux (char *buff, lua_Number x) {
         m = adddigit(buff, n++, m * 16);
       } while (m > 0);
     }
-    n += sprintf(buff + n, "p%+d", e);  /* add exponent */
+    n += l_sprintf(buff + n, sz - n, "p%+d", e);  /* add exponent */
+    lua_assert(n < sz);
     return n;
   }
 }
 
 
-static int lua_number2strx (lua_State *L, char *buff, const char *fmt,
-                            lua_Number x) {
-  int n = num2straux(buff, x);
+static int lua_number2strx (lua_State *L, char *buff, int sz,
+                            const char *fmt, lua_Number x) {
+  int n = num2straux(buff, sz, x);
   if (fmt[SIZELENMOD] == 'A') {
     int i;
     for (i = 0; i < n; i++)
       buff[i] = toupper(uchar(buff[i]));
   }
   else if (fmt[SIZELENMOD] != 'a')
-    luaL_error(L, "modifiers for format '%%a'/'%%A' not implemented");
+    return luaL_error(L, "modifiers for format '%%a'/'%%A' not implemented");
   return n;
 }
 
@@ -879,10 +888,12 @@ static int lua_number2strx (lua_State *L, char *buff, const char *fmt,
 
 /*
 ** Maximum size of each formatted item. This maximum size is produced
-** by format('%.99f', minfloat), and is equal to 99 + 2 ('-' and '.') +
-** number of decimal digits to represent minfloat.
+** by format('%.99f', -maxfloat), and is equal to 99 + 3 ('-', '.',
+** and '\0') + number of decimal digits to represent maxfloat (which
+** is maximum exponent + 1). (99+3+1 then rounded to 120 for "extra
+** expenses", such as locale-dependent stuff)
 */
-#define MAX_ITEM	(120 + l_mathlim(MAX_10_EXP))
+#define MAX_ITEM        (120 + l_mathlim(MAX_10_EXP))
 
 
 /* valid flags in a format specification */
@@ -894,21 +905,19 @@ static int lua_number2strx (lua_State *L, char *buff, const char *fmt,
 #define MAX_FORMAT	32
 
 
-static void addquoted (lua_State *L, luaL_Buffer *b, int arg) {
-  size_t l;
-  const char *s = luaL_checklstring(L, arg, &l);
+static void addquoted (luaL_Buffer *b, const char *s, size_t len) {
   luaL_addchar(b, '"');
-  while (l--) {
+  while (len--) {
     if (*s == '"' || *s == '\\' || *s == '\n') {
       luaL_addchar(b, '\\');
       luaL_addchar(b, *s);
     }
-    else if (*s == '\0' || iscntrl(uchar(*s))) {
+    else if (iscntrl(uchar(*s))) {
       char buff[10];
       if (!isdigit(uchar(*(s+1))))
-        sprintf(buff, "\\%d", (int)uchar(*s));
+        l_sprintf(buff, sizeof(buff), "\\%d", (int)uchar(*s));
       else
-        sprintf(buff, "\\%03d", (int)uchar(*s));
+        l_sprintf(buff, sizeof(buff), "\\%03d", (int)uchar(*s));
       luaL_addstring(b, buff);
     }
     else
@@ -918,6 +927,57 @@ static void addquoted (lua_State *L, luaL_Buffer *b, int arg) {
   luaL_addchar(b, '"');
 }
 
+
+/*
+** Ensures the 'buff' string uses a dot as the radix character.
+*/
+static void checkdp (char *buff, int nb) {
+  if (memchr(buff, '.', nb) == NULL) {  /* no dot? */
+    char point = lua_getlocaledecpoint();  /* try locale point */
+    char *ppoint = (char *)memchr(buff, point, nb);
+    if (ppoint) *ppoint = '.';  /* change it to a dot */
+  }
+}
+
+
+static void addliteral (lua_State *L, luaL_Buffer *b, int arg) {
+  switch (lua_type(L, arg)) {
+    case LUA_TSTRING: {
+      size_t len;
+      const char *s = lua_tolstring(L, arg, &len);
+      addquoted(b, s, len);
+      break;
+    }
+    case LUA_TNUMBER: {
+      char *buff = luaL_prepbuffsize(b, MAX_ITEM);
+      int nb;
+      if (!lua_isinteger(L, arg)) {  /* float? */
+        lua_Number n = lua_tonumber(L, arg);  /* write as hexa ('%a') */
+        nb = lua_number2strx(L, buff, MAX_ITEM, "%" LUA_NUMBER_FRMLEN "a", n);
+        checkdp(buff, nb);  /* ensure it uses a dot */
+      }
+      else {  /* integers */
+        lua_Integer n = lua_tointeger(L, arg);
+        const char *format = (n == LUA_MININTEGER)  /* corner case? */
+                           ? "0x%" LUA_INTEGER_FRMLEN "x"  /* use hexa */
+                           : LUA_INTEGER_FMT;  /* else use default format */
+        nb = l_sprintf(buff, MAX_ITEM, format, (LUAI_UACINT)n);
+      }
+      luaL_addsize(b, nb);
+      break;
+    }
+    case LUA_TNIL: case LUA_TBOOLEAN: {
+      luaL_tolstring(L, arg, NULL);
+      luaL_addvalue(b);
+      break;
+    }
+    default: {
+      luaL_argerror(L, arg, "value has no literal form");
+    }
+  }
+}
+
+
 static const char *scanformat (lua_State *L, const char *strfrmt, char *form) {
   const char *p = strfrmt;
   while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++;  /* skip flags */
@@ -975,41 +1035,47 @@ static int str_format (lua_State *L) {
       strfrmt = scanformat(L, strfrmt, form);
       switch (*strfrmt++) {
         case 'c': {
-          nb = sprintf(buff, form, (int)luaL_checkinteger(L, arg));
+          nb = l_sprintf(buff, MAX_ITEM, form, (int)luaL_checkinteger(L, arg));
           break;
         }
         case 'd': case 'i':
         case 'o': case 'u': case 'x': case 'X': {
           lua_Integer n = luaL_checkinteger(L, arg);
           addlenmod(form, LUA_INTEGER_FRMLEN);
-          nb = sprintf(buff, form, n);
+          nb = l_sprintf(buff, MAX_ITEM, form, (LUAI_UACINT)n);
           break;
         }
         case 'a': case 'A':
           addlenmod(form, LUA_NUMBER_FRMLEN);
-          nb = lua_number2strx(L, buff, form, luaL_checknumber(L, arg));
+          nb = lua_number2strx(L, buff, MAX_ITEM, form,
+                                  luaL_checknumber(L, arg));
           break;
         case 'e': case 'E': case 'f':
         case 'g': case 'G': {
+          lua_Number n = luaL_checknumber(L, arg);
           addlenmod(form, LUA_NUMBER_FRMLEN);
-          nb = sprintf(buff, form, luaL_checknumber(L, arg));
+          nb = l_sprintf(buff, MAX_ITEM, form, (LUAI_UACNUMBER)n);
           break;
         }
         case 'q': {
-          addquoted(L, &b, arg);
+          addliteral(L, &b, arg);
           break;
         }
         case 's': {
           size_t l;
           const char *s = luaL_tolstring(L, arg, &l);
-          if (!strchr(form, '.') && l >= 100) {
-            /* no precision and string is too long to be formatted;
-               keep original string */
-            luaL_addvalue(&b);
-          }
+          if (form[2] == '\0')  /* no modifiers? */
+            luaL_addvalue(&b);  /* keep entire string */
           else {
-            nb = sprintf(buff, form, s);
-            lua_pop(L, 1);  /* remove result from 'luaL_tolstring' */
+            luaL_argcheck(L, l == strlen(s), arg, "string contains zeros");
+            if (!strchr(form, '.') && l >= 100) {
+              /* no precision and string is too long to be formatted */
+              luaL_addvalue(&b);  /* keep entire string */
+            }
+            else {  /* format the string into 'buff' */
+              nb = l_sprintf(buff, MAX_ITEM, form, s);
+              lua_pop(L, 1);  /* remove result from 'luaL_tolstring' */
+            }
           }
           break;
         }
@@ -1018,6 +1084,7 @@ static int str_format (lua_State *L) {
                                *(strfrmt - 1));
         }
       }
+      lua_assert(nb < MAX_ITEM);
       luaL_addsize(&b, nb);
     }
   }
@@ -1036,8 +1103,8 @@ static int str_format (lua_State *L) {
 
 
 /* value used for padding */
-#if !defined(LUA_PACKPADBYTE)
-#define LUA_PACKPADBYTE		0x00
+#if !defined(LUAL_PACKPADBYTE)
+#define LUAL_PACKPADBYTE		0x00
 #endif
 
 /* maximum size for the binary representation of an integer */
@@ -1132,8 +1199,8 @@ static int getnum (const char **fmt, int df) {
 static int getnumlimit (Header *h, const char **fmt, int df) {
   int sz = getnum(fmt, df);
   if (sz > MAXINTSIZE || sz <= 0)
-    luaL_error(h->L, "integral size (%d) out of limits [1,%d]",
-                     sz, MAXINTSIZE);
+    return luaL_error(h->L, "integral size (%d) out of limits [1,%d]",
+                            sz, MAXINTSIZE);
   return sz;
 }
 
@@ -1194,7 +1261,7 @@ static KOption getoption (Header *h, const char **fmt, int *size) {
 ** 'psize' is filled with option's size, 'notoalign' with its
 ** alignment requirements.
 ** Local variable 'size' gets the size to be aligned. (Kpadal option
-** always gets its full alignment, other options are limited by 
+** always gets its full alignment, other options are limited by
 ** the maximum alignment ('maxalign'). Kchar option needs no alignment
 ** despite its size.
 */
@@ -1274,7 +1341,7 @@ static int str_pack (lua_State *L) {
     KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign);
     totalsize += ntoalign + size;
     while (ntoalign-- > 0)
-     luaL_addchar(&b, LUA_PACKPADBYTE);  /* fill alignment */
+     luaL_addchar(&b, LUAL_PACKPADBYTE);  /* fill alignment */
     arg++;
     switch (opt) {
       case Kint: {  /* signed integers */
@@ -1309,8 +1376,11 @@ static int str_pack (lua_State *L) {
       case Kchar: {  /* fixed-size string */
         size_t len;
         const char *s = luaL_checklstring(L, arg, &len);
-        luaL_argcheck(L, len == (size_t)size, arg, "wrong length");
-        luaL_addlstring(&b, s, size);
+        luaL_argcheck(L, len <= (size_t)size, arg,
+                         "string longer than given size");
+        luaL_addlstring(&b, s, len);  /* add string */
+        while (len++ < (size_t)size)  /* pad extra space */
+          luaL_addchar(&b, LUAL_PACKPADBYTE);
         break;
       }
       case Kstring: {  /* strings with length count */
@@ -1333,7 +1403,7 @@ static int str_pack (lua_State *L) {
         totalsize += len + 1;
         break;
       }
-      case Kpadding: luaL_addchar(&b, LUA_PACKPADBYTE);  /* FALLTHROUGH */
+      case Kpadding: luaL_addchar(&b, LUAL_PACKPADBYTE);  /* FALLTHROUGH */
       case Kpaddalign: case Knop:
         arg--;  /* undo increment */
         break;
@@ -1360,7 +1430,7 @@ static int str_packsize (lua_State *L) {
       case Kstring:  /* strings with length count */
       case Kzstr:    /* zero-terminated string */
         luaL_argerror(L, 1, "variable-length format");
-        break;
+        /* call never return, but to avoid warnings: *//* FALLTHROUGH */
       default:  break;
     }
   }
diff --git a/source/extern/lua/ltable.c b/source/extern/lua/ltable.c
index 04f2a34..ea4fe7f 100644
--- a/source/extern/lua/ltable.c
+++ b/source/extern/lua/ltable.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltable.c,v 2.111 2015/06/09 14:21:13 roberto Exp $
+** $Id: ltable.c,v 2.118.1.4 2018/06/08 16:22:51 roberto Exp $
 ** Lua tables (hash)
 ** See Copyright Notice in lua.h
 */
@@ -74,8 +74,6 @@
 
 #define dummynode		(&dummynode_)
 
-#define isdummy(n)		((n) == dummynode)
-
 static const Node dummynode_ = {
   {NILCONSTANT},  /* value */
   {{NILCONSTANT, 0}}  /* key */
@@ -85,7 +83,7 @@ static const Node dummynode_ = {
 /*
 ** Hash for floating-point numbers.
 ** The main computation should be just
-**     n = frepx(n, &i); return (n * INT_MAX) + i
+**     n = frexp(n, &i); return (n * INT_MAX) + i
 ** but there are some numerical subtleties.
 ** In a two-complement representation, INT_MAX does not has an exact
 ** representation as a float, but INT_MIN does; because the absolute
@@ -101,7 +99,7 @@ static int l_hashfloat (lua_Number n) {
   lua_Integer ni;
   n = l_mathop(frexp)(n, &i) * -cast_num(INT_MIN);
   if (!lua_numbertointeger(n, &ni)) {  /* is 'n' inf/-inf/NaN? */
-    lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == HUGE_VAL);
+    lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == cast_num(HUGE_VAL));
     return 0;
   }
   else {  /* normal case */
@@ -124,14 +122,8 @@ static Node *mainposition (const Table *t, const TValue *key) {
       return hashmod(t, l_hashfloat(fltvalue(key)));
     case LUA_TSHRSTR:
       return hashstr(t, tsvalue(key));
-    case LUA_TLNGSTR: {
-      TString *s = tsvalue(key);
-      if (s->extra == 0) {  /* no hash? */
-        s->hash = luaS_hash(getstr(s), s->u.lnglen, s->hash);
-        s->extra = 1;  /* now it has its hash */
-      }
-      return hashstr(t, tsvalue(key));
-    }
+    case LUA_TLNGSTR:
+      return hashpow2(t, luaS_hashlongstr(tsvalue(key)));
     case LUA_TBOOLEAN:
       return hashboolean(t, bvalue(key));
     case LUA_TLIGHTUSERDATA:
@@ -139,6 +131,7 @@ static Node *mainposition (const Table *t, const TValue *key) {
     case LUA_TLCF:
       return hashpointer(t, fvalue(key));
     default:
+      lua_assert(!ttisdeadkey(key));
       return hashpointer(t, gcvalue(key));
   }
 }
@@ -230,7 +223,9 @@ static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
   unsigned int na = 0;  /* number of elements to go to array part */
   unsigned int optimal = 0;  /* optimal size for array part */
   /* loop while keys can fill more than half of total size */
-  for (i = 0, twotoi = 1; *pna > twotoi / 2; i++, twotoi *= 2) {
+  for (i = 0, twotoi = 1;
+       twotoi > 0 && *pna > twotoi / 2;
+       i++, twotoi *= 2) {
     if (nums[i] > 0) {
       a += nums[i];
       if (a > twotoi/2) {  /* more than half elements present? */
@@ -313,14 +308,14 @@ static void setarrayvector (lua_State *L, Table *t, unsigned int size) {
 
 
 static void setnodevector (lua_State *L, Table *t, unsigned int size) {
-  int lsize;
   if (size == 0) {  /* no elements to hash part? */
     t->node = cast(Node *, dummynode);  /* use common 'dummynode' */
-    lsize = 0;
+    t->lsizenode = 0;
+    t->lastfree = NULL;  /* signal that it is using dummy node */
   }
   else {
     int i;
-    lsize = luaO_ceillog2(size);
+    int lsize = luaO_ceillog2(size);
     if (lsize > MAXHBITS)
       luaG_runerror(L, "table overflow");
     size = twoto(lsize);
@@ -331,9 +326,21 @@ static void setnodevector (lua_State *L, Table *t, unsigned int size) {
       setnilvalue(wgkey(n));
       setnilvalue(gval(n));
     }
+    t->lsizenode = cast_byte(lsize);
+    t->lastfree = gnode(t, size);  /* all positions are free */
   }
-  t->lsizenode = cast_byte(lsize);
-  t->lastfree = gnode(t, size);  /* all positions are free */
+}
+
+
+typedef struct {
+  Table *t;
+  unsigned int nhsize;
+} AuxsetnodeT;
+
+
+static void auxsetnode (lua_State *L, void *ud) {
+  AuxsetnodeT *asn = cast(AuxsetnodeT *, ud);
+  setnodevector(L, asn->t, asn->nhsize);
 }
 
 
@@ -341,13 +348,18 @@ void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
                                           unsigned int nhsize) {
   unsigned int i;
   int j;
+  AuxsetnodeT asn;
   unsigned int oldasize = t->sizearray;
-  int oldhsize = t->lsizenode;
+  int oldhsize = allocsizenode(t);
   Node *nold = t->node;  /* save old hash ... */
   if (nasize > oldasize)  /* array part must grow? */
     setarrayvector(L, t, nasize);
   /* create new hash part with appropriate size */
-  setnodevector(L, t, nhsize);
+  asn.t = t; asn.nhsize = nhsize;
+  if (luaD_rawrunprotected(L, auxsetnode, &asn) != LUA_OK) {  /* mem. error? */
+    setarrayvector(L, t, oldasize);  /* array back to its original size */
+    luaD_throw(L, LUA_ERRMEM);  /* rethrow memory error */
+  }
   if (nasize < oldasize) {  /* array part must shrink? */
     t->sizearray = nasize;
     /* re-insert elements from vanishing slice */
@@ -359,7 +371,7 @@ void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
     luaM_reallocvector(L, t->array, oldasize, nasize, TValue);
   }
   /* re-insert elements from hash part */
-  for (j = twoto(oldhsize) - 1; j >= 0; j--) {
+  for (j = oldhsize - 1; j >= 0; j--) {
     Node *old = nold + j;
     if (!ttisnil(gval(old))) {
       /* doesn't need barrier/invalidate cache, as entry was
@@ -367,13 +379,13 @@ void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
       setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old));
     }
   }
-  if (!isdummy(nold))
-    luaM_freearray(L, nold, cast(size_t, twoto(oldhsize))); /* free old hash */
+  if (oldhsize > 0)  /* not the dummy node? */
+    luaM_freearray(L, nold, cast(size_t, oldhsize)); /* free old hash */
 }
 
 
 void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) {
-  int nsize = isdummy(t->node) ? 0 : sizenode(t);
+  int nsize = allocsizenode(t);
   luaH_resize(L, t, nasize, nsize);
 }
 
@@ -419,7 +431,7 @@ Table *luaH_new (lua_State *L) {
 
 
 void luaH_free (lua_State *L, Table *t) {
-  if (!isdummy(t->node))
+  if (!isdummy(t))
     luaM_freearray(L, t->node, cast(size_t, sizenode(t)));
   luaM_freearray(L, t->array, t->sizearray);
   luaM_free(L, t);
@@ -427,10 +439,12 @@ void luaH_free (lua_State *L, Table *t) {
 
 
 static Node *getfreepos (Table *t) {
-  while (t->lastfree > t->node) {
-    t->lastfree--;
-    if (ttisnil(gkey(t->lastfree)))
-      return t->lastfree;
+  if (!isdummy(t)) {
+    while (t->lastfree > t->node) {
+      t->lastfree--;
+      if (ttisnil(gkey(t->lastfree)))
+        return t->lastfree;
+    }
   }
   return NULL;  /* could not find a free place */
 }
@@ -450,7 +464,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
   if (ttisnil(key)) luaG_runerror(L, "table index is nil");
   else if (ttisfloat(key)) {
     lua_Integer k;
-    if (luaV_tointeger(key, &k, 0)) {  /* index is int? */
+    if (luaV_tointeger(key, &k, 0)) {  /* does index fit in an integer? */
       setivalue(&aux, k);
       key = &aux;  /* insert it as an integer */
     }
@@ -458,15 +472,15 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
       luaG_runerror(L, "table index is NaN");
   }
   mp = mainposition(t, key);
-  if (!ttisnil(gval(mp)) || isdummy(mp)) {  /* main position is taken? */
+  if (!ttisnil(gval(mp)) || isdummy(t)) {  /* main position is taken? */
     Node *othern;
     Node *f = getfreepos(t);  /* get a free place */
     if (f == NULL) {  /* cannot find a free place? */
       rehash(L, t, key);  /* grow table */
-      /* whatever called 'newkey' takes care of TM cache and GC barrier */
+      /* whatever called 'newkey' takes care of TM cache */
       return luaH_set(L, t, key);  /* insert key into grown table */
     }
-    lua_assert(!isdummy(f));
+    lua_assert(!isdummy(t));
     othern = mainposition(t, gkey(mp));
     if (othern != mp) {  /* is colliding node out of its main position? */
       /* yes; move colliding node into free position */
@@ -501,7 +515,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
 */
 const TValue *luaH_getint (Table *t, lua_Integer key) {
   /* (1 <= key && key <= t->sizearray) */
-  if (l_castS2U(key - 1) < t->sizearray)
+  if (l_castS2U(key) - 1 < t->sizearray)
     return &t->array[key - 1];
   else {
     Node *n = hashint(t, key);
@@ -513,7 +527,7 @@ const TValue *luaH_getint (Table *t, lua_Integer key) {
         if (nx == 0) break;
         n += nx;
       }
-    };
+    }
     return luaO_nilobject;
   }
 }
@@ -522,7 +536,7 @@ const TValue *luaH_getint (Table *t, lua_Integer key) {
 /*
 ** search function for short strings
 */
-const TValue *luaH_getstr (Table *t, TString *key) {
+const TValue *luaH_getshortstr (Table *t, TString *key) {
   Node *n = hashstr(t, key);
   lua_assert(key->tt == LUA_TSHRSTR);
   for (;;) {  /* check whether 'key' is somewhere in the chain */
@@ -531,11 +545,41 @@ const TValue *luaH_getstr (Table *t, TString *key) {
       return gval(n);  /* that's it */
     else {
       int nx = gnext(n);
-      if (nx == 0) break;
+      if (nx == 0)
+        return luaO_nilobject;  /* not found */
       n += nx;
     }
-  };
-  return luaO_nilobject;
+  }
+}
+
+
+/*
+** "Generic" get version. (Not that generic: not valid for integers,
+** which may be in array part, nor for floats with integral values.)
+*/
+static const TValue *getgeneric (Table *t, const TValue *key) {
+  Node *n = mainposition(t, key);
+  for (;;) {  /* check whether 'key' is somewhere in the chain */
+    if (luaV_rawequalobj(gkey(n), key))
+      return gval(n);  /* that's it */
+    else {
+      int nx = gnext(n);
+      if (nx == 0)
+        return luaO_nilobject;  /* not found */
+      n += nx;
+    }
+  }
+}
+
+
+const TValue *luaH_getstr (Table *t, TString *key) {
+  if (key->tt == LUA_TSHRSTR)
+    return luaH_getshortstr(t, key);
+  else {  /* for long strings, use generic case */
+    TValue ko;
+    setsvalue(cast(lua_State *, NULL), &ko, key);
+    return getgeneric(t, &ko);
+  }
 }
 
 
@@ -544,7 +588,7 @@ const TValue *luaH_getstr (Table *t, TString *key) {
 */
 const TValue *luaH_get (Table *t, const TValue *key) {
   switch (ttype(key)) {
-    case LUA_TSHRSTR: return luaH_getstr(t, tsvalue(key));
+    case LUA_TSHRSTR: return luaH_getshortstr(t, tsvalue(key));
     case LUA_TNUMINT: return luaH_getint(t, ivalue(key));
     case LUA_TNIL: return luaO_nilobject;
     case LUA_TNUMFLT: {
@@ -553,19 +597,8 @@ const TValue *luaH_get (Table *t, const TValue *key) {
         return luaH_getint(t, k);  /* use specialized version */
       /* else... */
     }  /* FALLTHROUGH */
-    default: {
-      Node *n = mainposition(t, key);
-      for (;;) {  /* check whether 'key' is somewhere in the chain */
-        if (luaV_rawequalobj(gkey(n), key))
-          return gval(n);  /* that's it */
-        else {
-          int nx = gnext(n);
-          if (nx == 0) break;
-          n += nx;
-        }
-      };
-      return luaO_nilobject;
-    }
+    default:
+      return getgeneric(t, key);
   }
 }
 
@@ -596,13 +629,13 @@ void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) {
 }
 
 
-static int unbound_search (Table *t, unsigned int j) {
-  unsigned int i = j;  /* i is zero or a present index */
+static lua_Unsigned unbound_search (Table *t, lua_Unsigned j) {
+  lua_Unsigned i = j;  /* i is zero or a present index */
   j++;
   /* find 'i' and 'j' such that i is present and j is not */
   while (!ttisnil(luaH_getint(t, j))) {
     i = j;
-    if (j > cast(unsigned int, MAX_INT)/2) {  /* overflow? */
+    if (j > l_castS2U(LUA_MAXINTEGER) / 2) {  /* overflow? */
       /* table was built with bad purposes: resort to linear search */
       i = 1;
       while (!ttisnil(luaH_getint(t, i))) i++;
@@ -612,7 +645,7 @@ static int unbound_search (Table *t, unsigned int j) {
   }
   /* now do a binary search between them */
   while (j - i > 1) {
-    unsigned int m = (i+j)/2;
+    lua_Unsigned m = (i+j)/2;
     if (ttisnil(luaH_getint(t, m))) j = m;
     else i = m;
   }
@@ -624,7 +657,7 @@ static int unbound_search (Table *t, unsigned int j) {
 ** Try to find a boundary in table 't'. A 'boundary' is an integer index
 ** such that t[i] is non-nil and t[i+1] is nil (and 0 if t[1] is nil).
 */
-int luaH_getn (Table *t) {
+lua_Unsigned luaH_getn (Table *t) {
   unsigned int j = t->sizearray;
   if (j > 0 && ttisnil(&t->array[j - 1])) {
     /* there is a boundary in the array part: (binary) search for it */
@@ -637,7 +670,7 @@ int luaH_getn (Table *t) {
     return i;
   }
   /* else must find a boundary in hash part */
-  else if (isdummy(t->node))  /* hash part is empty? */
+  else if (isdummy(t))  /* hash part is empty? */
     return j;  /* that is easy... */
   else return unbound_search(t, j);
 }
@@ -650,6 +683,6 @@ Node *luaH_mainposition (const Table *t, const TValue *key) {
   return mainposition(t, key);
 }
 
-int luaH_isdummy (Node *n) { return isdummy(n); }
+int luaH_isdummy (const Table *t) { return isdummy(t); }
 
 #endif
diff --git a/source/extern/lua/ltable.h b/source/extern/lua/ltable.h
index 53d2551..92db0ac 100644
--- a/source/extern/lua/ltable.h
+++ b/source/extern/lua/ltable.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ltable.h,v 2.20 2014/09/04 18:15:29 roberto Exp $
+** $Id: ltable.h,v 2.23.1.2 2018/05/24 19:39:05 roberto Exp $
 ** Lua tables (hash)
 ** See Copyright Notice in lua.h
 */
@@ -15,14 +15,26 @@
 #define gnext(n)	((n)->i_key.nk.next)
 
 
-/* 'const' to avoid wrong writings that can mess up field 'next' */ 
+/* 'const' to avoid wrong writings that can mess up field 'next' */
 #define gkey(n)		cast(const TValue*, (&(n)->i_key.tvk))
 
+/*
+** writable version of 'gkey'; allows updates to individual fields,
+** but not to the whole (which has incompatible type)
+*/
 #define wgkey(n)		(&(n)->i_key.nk)
 
 #define invalidateTMcache(t)	((t)->flags = 0)
 
 
+/* true when 't' is using 'dummynode' as its hash part */
+#define isdummy(t)		((t)->lastfree == NULL)
+
+
+/* allocated size for hash nodes */
+#define allocsizenode(t)	(isdummy(t) ? 0 : sizenode(t))
+
+
 /* returns the key, given the value of a table entry */
 #define keyfromval(v) \
   (gkey(cast(Node *, cast(char *, (v)) - offsetof(Node, i_val))))
@@ -31,6 +43,7 @@
 LUAI_FUNC const TValue *luaH_getint (Table *t, lua_Integer key);
 LUAI_FUNC void luaH_setint (lua_State *L, Table *t, lua_Integer key,
                                                     TValue *value);
+LUAI_FUNC const TValue *luaH_getshortstr (Table *t, TString *key);
 LUAI_FUNC const TValue *luaH_getstr (Table *t, TString *key);
 LUAI_FUNC const TValue *luaH_get (Table *t, const TValue *key);
 LUAI_FUNC TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key);
@@ -41,12 +54,12 @@ LUAI_FUNC void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
 LUAI_FUNC void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize);
 LUAI_FUNC void luaH_free (lua_State *L, Table *t);
 LUAI_FUNC int luaH_next (lua_State *L, Table *t, StkId key);
-LUAI_FUNC int luaH_getn (Table *t);
+LUAI_FUNC lua_Unsigned luaH_getn (Table *t);
 
 
 #if defined(LUA_DEBUG)
 LUAI_FUNC Node *luaH_mainposition (const Table *t, const TValue *key);
-LUAI_FUNC int luaH_isdummy (Node *n);
+LUAI_FUNC int luaH_isdummy (const Table *t);
 #endif
 
 
diff --git a/source/extern/lua/ltablib.c b/source/extern/lua/ltablib.c
index a05c885..c534957 100644
--- a/source/extern/lua/ltablib.c
+++ b/source/extern/lua/ltablib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltablib.c,v 1.80 2015/01/13 16:27:29 roberto Exp $
+** $Id: ltablib.c,v 1.93.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Library for Table Manipulation
 ** See Copyright Notice in lua.h
 */
@@ -12,6 +12,7 @@
 
 #include <limits.h>
 #include <stddef.h>
+#include <string.h>
 
 #include "lua.h"
 
@@ -19,40 +20,42 @@
 #include "lualib.h"
 
 
-
 /*
-** Structure with table-access functions
+** Operations that an object must define to mimic a table
+** (some functions only need some of them)
 */
-typedef struct {
-  int (*geti) (lua_State *L, int idx, lua_Integer n);
-  void (*seti) (lua_State *L, int idx, lua_Integer n);
-} TabA;
+#define TAB_R	1			/* read */
+#define TAB_W	2			/* write */
+#define TAB_L	4			/* length */
+#define TAB_RW	(TAB_R | TAB_W)		/* read/write */
 
 
-/*
-** Check that 'arg' has a table and set access functions in 'ta' to raw
-** or non-raw according to the presence of corresponding metamethods.
-*/
-static void checktab (lua_State *L, int arg, TabA *ta) {
-  ta->geti = NULL; ta->seti = NULL;
-  if (lua_getmetatable(L, arg)) {
-    lua_pushliteral(L, "__index");  /* 'index' metamethod */
-    if (lua_rawget(L, -2) != LUA_TNIL)
-      ta->geti = lua_geti;
-    lua_pushliteral(L, "__newindex");  /* 'newindex' metamethod */
-    if (lua_rawget(L, -3) != LUA_TNIL)
-      ta->seti = lua_seti;
-    lua_pop(L, 3);  /* pop metatable plus both metamethods */
-  }
-  if (ta->geti == NULL || ta->seti == NULL) {
-    luaL_checktype(L, arg, LUA_TTABLE);  /* must be table for raw methods */
-    if (ta->geti == NULL) ta->geti = lua_rawgeti;
-    if (ta->seti == NULL) ta->seti = lua_rawseti;
-  }
+#define aux_getn(L,n,w)	(checktab(L, n, (w) | TAB_L), luaL_len(L, n))
+
+
+static int checkfield (lua_State *L, const char *key, int n) {
+  lua_pushstring(L, key);
+  return (lua_rawget(L, -n) != LUA_TNIL);
 }
 
 
-#define aux_getn(L,n,ta)	(checktab(L, n, ta), luaL_len(L, n))
+/*
+** Check that 'arg' either is a table or can behave like one (that is,
+** has a metatable with the required metamethods)
+*/
+static void checktab (lua_State *L, int arg, int what) {
+  if (lua_type(L, arg) != LUA_TTABLE) {  /* is it not a table? */
+    int n = 1;  /* number of elements to pop */
+    if (lua_getmetatable(L, arg) &&  /* must have metatable */
+        (!(what & TAB_R) || checkfield(L, "__index", ++n)) &&
+        (!(what & TAB_W) || checkfield(L, "__newindex", ++n)) &&
+        (!(what & TAB_L) || checkfield(L, "__len", ++n))) {
+      lua_pop(L, n);  /* pop metatable and tested metamethods */
+    }
+    else
+      luaL_checktype(L, arg, LUA_TTABLE);  /* force an error */
+  }
+}
 
 
 #if defined(LUA_COMPAT_MAXN)
@@ -74,8 +77,7 @@ static int maxn (lua_State *L) {
 
 
 static int tinsert (lua_State *L) {
-  TabA ta;
-  lua_Integer e = aux_getn(L, 1, &ta) + 1;  /* first empty element */
+  lua_Integer e = aux_getn(L, 1, TAB_RW) + 1;  /* first empty element */
   lua_Integer pos;  /* where to insert new element */
   switch (lua_gettop(L)) {
     case 2: {  /* called with only 2 arguments */
@@ -87,8 +89,8 @@ static int tinsert (lua_State *L) {
       pos = luaL_checkinteger(L, 2);  /* 2nd argument is the position */
       luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
       for (i = e; i > pos; i--) {  /* move up elements */
-        (*ta.geti)(L, 1, i - 1);
-        (*ta.seti)(L, 1, i);  /* t[i] = t[i - 1] */
+        lua_geti(L, 1, i - 1);
+        lua_seti(L, 1, i);  /* t[i] = t[i - 1] */
       }
       break;
     }
@@ -96,67 +98,67 @@ static int tinsert (lua_State *L) {
       return luaL_error(L, "wrong number of arguments to 'insert'");
     }
   }
-  (*ta.seti)(L, 1, pos);  /* t[pos] = v */
+  lua_seti(L, 1, pos);  /* t[pos] = v */
   return 0;
 }
 
 
 static int tremove (lua_State *L) {
-  TabA ta;
-  lua_Integer size = aux_getn(L, 1, &ta);
+  lua_Integer size = aux_getn(L, 1, TAB_RW);
   lua_Integer pos = luaL_optinteger(L, 2, size);
   if (pos != size)  /* validate 'pos' if given */
     luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
-  (*ta.geti)(L, 1, pos);  /* result = t[pos] */
+  lua_geti(L, 1, pos);  /* result = t[pos] */
   for ( ; pos < size; pos++) {
-    (*ta.geti)(L, 1, pos + 1);
-    (*ta.seti)(L, 1, pos);  /* t[pos] = t[pos + 1] */
+    lua_geti(L, 1, pos + 1);
+    lua_seti(L, 1, pos);  /* t[pos] = t[pos + 1] */
   }
   lua_pushnil(L);
-  (*ta.seti)(L, 1, pos);  /* t[pos] = nil */
+  lua_seti(L, 1, pos);  /* t[pos] = nil */
   return 1;
 }
 
 
+/*
+** Copy elements (1[f], ..., 1[e]) into (tt[t], tt[t+1], ...). Whenever
+** possible, copy in increasing order, which is better for rehashing.
+** "possible" means destination after original range, or smaller
+** than origin, or copying to another table.
+*/
 static int tmove (lua_State *L) {
-  TabA ta;
   lua_Integer f = luaL_checkinteger(L, 2);
   lua_Integer e = luaL_checkinteger(L, 3);
   lua_Integer t = luaL_checkinteger(L, 4);
   int tt = !lua_isnoneornil(L, 5) ? 5 : 1;  /* destination table */
+  checktab(L, 1, TAB_R);
+  checktab(L, tt, TAB_W);
   if (e >= f) {  /* otherwise, nothing to move */
     lua_Integer n, i;
-    ta.geti = (luaL_getmetafield(L, 1, "__index") == LUA_TNIL)
-      ? (luaL_checktype(L, 1, LUA_TTABLE), lua_rawgeti)
-      : lua_geti;
-    ta.seti = (luaL_getmetafield(L, tt, "__newindex") == LUA_TNIL)
-      ? (luaL_checktype(L, tt, LUA_TTABLE), lua_rawseti)
-      : lua_seti;
     luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3,
                   "too many elements to move");
     n = e - f + 1;  /* number of elements to move */
     luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4,
                   "destination wrap around");
-    if (t > f) {
-      for (i = n - 1; i >= 0; i--) {
-        (*ta.geti)(L, 1, f + i);
-        (*ta.seti)(L, tt, t + i);
+    if (t > e || t <= f || (tt != 1 && !lua_compare(L, 1, tt, LUA_OPEQ))) {
+      for (i = 0; i < n; i++) {
+        lua_geti(L, 1, f + i);
+        lua_seti(L, tt, t + i);
       }
     }
     else {
-      for (i = 0; i < n; i++) {
-        (*ta.geti)(L, 1, f + i);
-        (*ta.seti)(L, tt, t + i);
+      for (i = n - 1; i >= 0; i--) {
+        lua_geti(L, 1, f + i);
+        lua_seti(L, tt, t + i);
       }
     }
   }
-  lua_pushvalue(L, tt);  /* return "to table" */
+  lua_pushvalue(L, tt);  /* return destination table */
   return 1;
 }
 
 
-static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) {
-  (*ta->geti)(L, 1, i);
+static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) {
+  lua_geti(L, 1, i);
   if (!lua_isstring(L, -1))
     luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
                   luaL_typename(L, -1), i);
@@ -165,21 +167,19 @@ static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) {
 
 
 static int tconcat (lua_State *L) {
-  TabA ta;
   luaL_Buffer b;
+  lua_Integer last = aux_getn(L, 1, TAB_R);
   size_t lsep;
-  lua_Integer i, last;
   const char *sep = luaL_optlstring(L, 2, "", &lsep);
-  checktab(L, 1, &ta);
-  i = luaL_optinteger(L, 3, 1);
-  last = luaL_opt(L, luaL_checkinteger, 4, luaL_len(L, 1));
+  lua_Integer i = luaL_optinteger(L, 3, 1);
+  last = luaL_optinteger(L, 4, last);
   luaL_buffinit(L, &b);
   for (; i < last; i++) {
-    addfield(L, &b, &ta, i);
+    addfield(L, &b, i);
     luaL_addlstring(&b, sep, lsep);
   }
   if (i == last)  /* add last value (if interval was not empty) */
-    addfield(L, &b, &ta, i);
+    addfield(L, &b, i);
   luaL_pushresult(&b);
   return 1;
 }
@@ -197,7 +197,7 @@ static int pack (lua_State *L) {
   lua_createtable(L, n, 1);  /* create result table */
   lua_insert(L, 1);  /* put it at index 1 */
   for (i = n; i >= 1; i--)  /* assign elements */
-    lua_rawseti(L, 1, i);
+    lua_seti(L, 1, i);
   lua_pushinteger(L, n);
   lua_setfield(L, 1, "n");  /* t.n = number of elements */
   return 1;  /* return table */
@@ -205,20 +205,17 @@ static int pack (lua_State *L) {
 
 
 static int unpack (lua_State *L) {
-  TabA ta;
-  lua_Integer i, e;
   lua_Unsigned n;
-  checktab(L, 1, &ta);
-  i = luaL_optinteger(L, 2, 1);
-  e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
+  lua_Integer i = luaL_optinteger(L, 2, 1);
+  lua_Integer e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
   if (i > e) return 0;  /* empty range */
   n = (lua_Unsigned)e - i;  /* number of elements minus 1 (avoid overflows) */
   if (n >= (unsigned int)INT_MAX  || !lua_checkstack(L, (int)(++n)))
     return luaL_error(L, "too many results to unpack");
-  do {  /* must have at least one element */
-    (*ta.geti)(L, 1, i);  /* push arg[i..e] */
-  } while (i++ < e); 
-
+  for (; i < e; i++) {  /* push arg[i..e - 1] (to avoid overflows) */
+    lua_geti(L, 1, i);
+  }
+  lua_geti(L, 1, e);  /* push last element */
   return (int)n;
 }
 
@@ -235,97 +232,191 @@ static int unpack (lua_State *L) {
 */
 
 
-static void set2 (lua_State *L, TabA *ta, int i, int j) {
-  (*ta->seti)(L, 1, i);
-  (*ta->seti)(L, 1, j);
+/* type for array indices */
+typedef unsigned int IdxT;
+
+
+/*
+** Produce a "random" 'unsigned int' to randomize pivot choice. This
+** macro is used only when 'sort' detects a big imbalance in the result
+** of a partition. (If you don't want/need this "randomness", ~0 is a
+** good choice.)
+*/
+#if !defined(l_randomizePivot)		/* { */
+
+#include <time.h>
+
+/* size of 'e' measured in number of 'unsigned int's */
+#define sof(e)		(sizeof(e) / sizeof(unsigned int))
+
+/*
+** Use 'time' and 'clock' as sources of "randomness". Because we don't
+** know the types 'clock_t' and 'time_t', we cannot cast them to
+** anything without risking overflows. A safe way to use their values
+** is to copy them to an array of a known type and use the array values.
+*/
+static unsigned int l_randomizePivot (void) {
+  clock_t c = clock();
+  time_t t = time(NULL);
+  unsigned int buff[sof(c) + sof(t)];
+  unsigned int i, rnd = 0;
+  memcpy(buff, &c, sof(c) * sizeof(unsigned int));
+  memcpy(buff + sof(c), &t, sof(t) * sizeof(unsigned int));
+  for (i = 0; i < sof(buff); i++)
+    rnd += buff[i];
+  return rnd;
 }
 
+#endif					/* } */
+
+
+/* arrays larger than 'RANLIMIT' may use randomized pivots */
+#define RANLIMIT	100u
+
+
+static void set2 (lua_State *L, IdxT i, IdxT j) {
+  lua_seti(L, 1, i);
+  lua_seti(L, 1, j);
+}
+
+
+/*
+** Return true iff value at stack index 'a' is less than the value at
+** index 'b' (according to the order of the sort).
+*/
 static int sort_comp (lua_State *L, int a, int b) {
-  if (!lua_isnil(L, 2)) {  /* function? */
+  if (lua_isnil(L, 2))  /* no function? */
+    return lua_compare(L, a, b, LUA_OPLT);  /* a < b */
+  else {  /* function */
     int res;
-    lua_pushvalue(L, 2);
+    lua_pushvalue(L, 2);    /* push function */
     lua_pushvalue(L, a-1);  /* -1 to compensate function */
     lua_pushvalue(L, b-2);  /* -2 to compensate function and 'a' */
-    lua_call(L, 2, 1);
-    res = lua_toboolean(L, -1);
-    lua_pop(L, 1);
+    lua_call(L, 2, 1);      /* call function */
+    res = lua_toboolean(L, -1);  /* get result */
+    lua_pop(L, 1);          /* pop result */
     return res;
   }
-  else  /* a < b? */
-    return lua_compare(L, a, b, LUA_OPLT);
 }
 
-static void auxsort (lua_State *L, TabA *ta, int l, int u) {
-  while (l < u) {  /* for tail recursion */
-    int i, j;
-    /* sort elements a[l], a[(l+u)/2] and a[u] */
-    (*ta->geti)(L, 1, l);
-    (*ta->geti)(L, 1, u);
-    if (sort_comp(L, -1, -2))  /* a[u] < a[l]? */
-      set2(L, ta, l, u);  /* swap a[l] - a[u] */
+
+/*
+** Does the partition: Pivot P is at the top of the stack.
+** precondition: a[lo] <= P == a[up-1] <= a[up],
+** so it only needs to do the partition from lo + 1 to up - 2.
+** Pos-condition: a[lo .. i - 1] <= a[i] == P <= a[i + 1 .. up]
+** returns 'i'.
+*/
+static IdxT partition (lua_State *L, IdxT lo, IdxT up) {
+  IdxT i = lo;  /* will be incremented before first use */
+  IdxT j = up - 1;  /* will be decremented before first use */
+  /* loop invariant: a[lo .. i] <= P <= a[j .. up] */
+  for (;;) {
+    /* next loop: repeat ++i while a[i] < P */
+    while (lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
+      if (i == up - 1)  /* a[i] < P  but a[up - 1] == P  ?? */
+        luaL_error(L, "invalid order function for sorting");
+      lua_pop(L, 1);  /* remove a[i] */
+    }
+    /* after the loop, a[i] >= P and a[lo .. i - 1] < P */
+    /* next loop: repeat --j while P < a[j] */
+    while (lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
+      if (j < i)  /* j < i  but  a[j] > P ?? */
+        luaL_error(L, "invalid order function for sorting");
+      lua_pop(L, 1);  /* remove a[j] */
+    }
+    /* after the loop, a[j] <= P and a[j + 1 .. up] >= P */
+    if (j < i) {  /* no elements out of place? */
+      /* a[lo .. i - 1] <= P <= a[j + 1 .. i .. up] */
+      lua_pop(L, 1);  /* pop a[j] */
+      /* swap pivot (a[up - 1]) with a[i] to satisfy pos-condition */
+      set2(L, up - 1, i);
+      return i;
+    }
+    /* otherwise, swap a[i] - a[j] to restore invariant and repeat */
+    set2(L, i, j);
+  }
+}
+
+
+/*
+** Choose an element in the middle (2nd-3th quarters) of [lo,up]
+** "randomized" by 'rnd'
+*/
+static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) {
+  IdxT r4 = (up - lo) / 4;  /* range/4 */
+  IdxT p = rnd % (r4 * 2) + (lo + r4);
+  lua_assert(lo + r4 <= p && p <= up - r4);
+  return p;
+}
+
+
+/*
+** QuickSort algorithm (recursive function)
+*/
+static void auxsort (lua_State *L, IdxT lo, IdxT up,
+                                   unsigned int rnd) {
+  while (lo < up) {  /* loop for tail recursion */
+    IdxT p;  /* Pivot index */
+    IdxT n;  /* to be used later */
+    /* sort elements 'lo', 'p', and 'up' */
+    lua_geti(L, 1, lo);
+    lua_geti(L, 1, up);
+    if (sort_comp(L, -1, -2))  /* a[up] < a[lo]? */
+      set2(L, lo, up);  /* swap a[lo] - a[up] */
     else
-      lua_pop(L, 2);
-    if (u-l == 1) break;  /* only 2 elements */
-    i = (l+u)/2;
-    (*ta->geti)(L, 1, i);
-    (*ta->geti)(L, 1, l);
-    if (sort_comp(L, -2, -1))  /* a[i]<a[l]? */
-      set2(L, ta, i, l);
+      lua_pop(L, 2);  /* remove both values */
+    if (up - lo == 1)  /* only 2 elements? */
+      return;  /* already sorted */
+    if (up - lo < RANLIMIT || rnd == 0)  /* small interval or no randomize? */
+      p = (lo + up)/2;  /* middle element is a good pivot */
+    else  /* for larger intervals, it is worth a random pivot */
+      p = choosePivot(lo, up, rnd);
+    lua_geti(L, 1, p);
+    lua_geti(L, 1, lo);
+    if (sort_comp(L, -2, -1))  /* a[p] < a[lo]? */
+      set2(L, p, lo);  /* swap a[p] - a[lo] */
     else {
-      lua_pop(L, 1);  /* remove a[l] */
-      (*ta->geti)(L, 1, u);
-      if (sort_comp(L, -1, -2))  /* a[u]<a[i]? */
-        set2(L, ta, i, u);
+      lua_pop(L, 1);  /* remove a[lo] */
+      lua_geti(L, 1, up);
+      if (sort_comp(L, -1, -2))  /* a[up] < a[p]? */
+        set2(L, p, up);  /* swap a[up] - a[p] */
       else
         lua_pop(L, 2);
     }
-    if (u-l == 2) break;  /* only 3 elements */
-    (*ta->geti)(L, 1, i);  /* Pivot */
-    lua_pushvalue(L, -1);
-    (*ta->geti)(L, 1, u-1);
-    set2(L, ta, i, u-1);
-    /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
-    i = l; j = u-1;
-    for (;;) {  /* invariant: a[l..i] <= P <= a[j..u] */
-      /* repeat ++i until a[i] >= P */
-      while ((*ta->geti)(L, 1, ++i), sort_comp(L, -1, -2)) {
-        if (i>=u) luaL_error(L, "invalid order function for sorting");
-        lua_pop(L, 1);  /* remove a[i] */
-      }
-      /* repeat --j until a[j] <= P */
-      while ((*ta->geti)(L, 1, --j), sort_comp(L, -3, -1)) {
-        if (j<=l) luaL_error(L, "invalid order function for sorting");
-        lua_pop(L, 1);  /* remove a[j] */
-      }
-      if (j<i) {
-        lua_pop(L, 3);  /* pop pivot, a[i], a[j] */
-        break;
-      }
-      set2(L, ta, i, j);
-    }
-    (*ta->geti)(L, 1, u-1);
-    (*ta->geti)(L, 1, i);
-    set2(L, ta, u-1, i);  /* swap pivot (a[u-1]) with a[i] */
-    /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
-    /* adjust so that smaller half is in [j..i] and larger one in [l..u] */
-    if (i-l < u-i) {
-      j=l; i=i-1; l=i+2;
+    if (up - lo == 2)  /* only 3 elements? */
+      return;  /* already sorted */
+    lua_geti(L, 1, p);  /* get middle element (Pivot) */
+    lua_pushvalue(L, -1);  /* push Pivot */
+    lua_geti(L, 1, up - 1);  /* push a[up - 1] */
+    set2(L, p, up - 1);  /* swap Pivot (a[p]) with a[up - 1] */
+    p = partition(L, lo, up);
+    /* a[lo .. p - 1] <= a[p] == P <= a[p + 1 .. up] */
+    if (p - lo < up - p) {  /* lower interval is smaller? */
+      auxsort(L, lo, p - 1, rnd);  /* call recursively for lower interval */
+      n = p - lo;  /* size of smaller interval */
+      lo = p + 1;  /* tail call for [p + 1 .. up] (upper interval) */
     }
     else {
-      j=i+1; i=u; u=j-2;
+      auxsort(L, p + 1, up, rnd);  /* call recursively for upper interval */
+      n = up - p;  /* size of smaller interval */
+      up = p - 1;  /* tail call for [lo .. p - 1]  (lower interval) */
     }
-    auxsort(L, ta, j, i);  /* call recursively the smaller one */
-  }  /* repeat the routine for the larger one */
+    if ((up - lo) / 128 > n) /* partition too imbalanced? */
+      rnd = l_randomizePivot();  /* try a new randomization */
+  }  /* tail call auxsort(L, lo, up, rnd) */
 }
 
+
 static int sort (lua_State *L) {
-  TabA ta;
-  int n = (int)aux_getn(L, 1, &ta);
-  luaL_checkstack(L, 50, "");  /* assume array is smaller than 2^50 */
-  if (!lua_isnoneornil(L, 2))  /* is there a 2nd argument? */
-    luaL_checktype(L, 2, LUA_TFUNCTION);
-  lua_settop(L, 2);  /* make sure there are two arguments */
-  auxsort(L, &ta, 1, n);
+  lua_Integer n = aux_getn(L, 1, TAB_RW);
+  if (n > 1) {  /* non-trivial interval? */
+    luaL_argcheck(L, n < INT_MAX, 1, "array too big");
+    if (!lua_isnoneornil(L, 2))  /* is there a 2nd argument? */
+      luaL_checktype(L, 2, LUA_TFUNCTION);  /* must be a function */
+    lua_settop(L, 2);  /* make sure there are two arguments */
+    auxsort(L, 1, (IdxT)n, 0);
+  }
   return 0;
 }
 
diff --git a/source/extern/lua/ltm.c b/source/extern/lua/ltm.c
index c38e5c3..0e7c713 100644
--- a/source/extern/lua/ltm.c
+++ b/source/extern/lua/ltm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.c,v 2.34 2015/03/30 15:42:27 roberto Exp $
+** $Id: ltm.c,v 2.38.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -15,7 +15,7 @@
 #include "lua.h"
 
 #include "ldebug.h"
-#include "ldo.h" 
+#include "ldo.h"
 #include "lobject.h"
 #include "lstate.h"
 #include "lstring.h"
@@ -57,7 +57,7 @@ void luaT_init (lua_State *L) {
 ** tag methods
 */
 const TValue *luaT_gettm (Table *events, TMS event, TString *ename) {
-  const TValue *tm = luaH_getstr(events, ename);
+  const TValue *tm = luaH_getshortstr(events, ename);
   lua_assert(event <= TM_EQ);
   if (ttisnil(tm)) {  /* no tag method? */
     events->flags |= cast_byte(1u<<event);  /* cache this fact */
@@ -79,20 +79,41 @@ const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) {
     default:
       mt = G(L)->mt[ttnov(o)];
   }
-  return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject);
+  return (mt ? luaH_getshortstr(mt, G(L)->tmname[event]) : luaO_nilobject);
+}
+
+
+/*
+** Return the name of the type of an object. For tables and userdata
+** with metatable, use their '__name' metafield, if present.
+*/
+const char *luaT_objtypename (lua_State *L, const TValue *o) {
+  Table *mt;
+  if ((ttistable(o) && (mt = hvalue(o)->metatable) != NULL) ||
+      (ttisfulluserdata(o) && (mt = uvalue(o)->metatable) != NULL)) {
+    const TValue *name = luaH_getshortstr(mt, luaS_new(L, "__name"));
+    if (ttisstring(name))  /* is '__name' a string? */
+      return getstr(tsvalue(name));  /* use it as type name */
+  }
+  return ttypename(ttnov(o));  /* else use standard type name */
 }
 
 
 void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
                   const TValue *p2, TValue *p3, int hasres) {
   ptrdiff_t result = savestack(L, p3);
-  setobj2s(L, L->top++, f);  /* push function (assume EXTRA_STACK) */
-  setobj2s(L, L->top++, p1);  /* 1st argument */
-  setobj2s(L, L->top++, p2);  /* 2nd argument */
+  StkId func = L->top;
+  setobj2s(L, func, f);  /* push function (assume EXTRA_STACK) */
+  setobj2s(L, func + 1, p1);  /* 1st argument */
+  setobj2s(L, func + 2, p2);  /* 2nd argument */
+  L->top += 3;
   if (!hasres)  /* no result? 'p3' is third argument */
     setobj2s(L, L->top++, p3);  /* 3rd argument */
   /* metamethod may yield only when called from Lua code */
-  luaD_call(L, L->top - (4 - hasres), hasres, isLua(L->ci));
+  if (isLua(L->ci))
+    luaD_call(L, func, hasres);
+  else
+    luaD_callnoyield(L, func, hasres);
   if (hasres) {  /* if has result, move it to its place */
     p3 = restorestack(L, result);
     setobjs2s(L, p3, --L->top);
diff --git a/source/extern/lua/ltm.h b/source/extern/lua/ltm.h
index 180179c..8170688 100644
--- a/source/extern/lua/ltm.h
+++ b/source/extern/lua/ltm.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.h,v 2.21 2014/10/25 11:50:46 roberto Exp $
+** $Id: ltm.h,v 2.22.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -51,11 +51,12 @@ typedef enum {
 #define fasttm(l,et,e)	gfasttm(G(l), et, e)
 
 #define ttypename(x)	luaT_typenames_[(x) + 1]
-#define objtypename(x)	ttypename(ttnov(x))
 
 LUAI_DDEC const char *const luaT_typenames_[LUA_TOTALTAGS];
 
 
+LUAI_FUNC const char *luaT_objtypename (lua_State *L, const TValue *o);
+
 LUAI_FUNC const TValue *luaT_gettm (Table *events, TMS event, TString *ename);
 LUAI_FUNC const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o,
                                                        TMS event);
diff --git a/source/extern/lua/lundump.c b/source/extern/lua/lundump.c
index 510f325..edf9eb8 100644
--- a/source/extern/lua/lundump.c
+++ b/source/extern/lua/lundump.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lundump.c,v 2.41 2014/11/02 19:19:04 roberto Exp $
+** $Id: lundump.c,v 2.44.1.1 2017/04/19 17:20:42 roberto Exp $
 ** load precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -32,7 +32,6 @@
 typedef struct {
   lua_State *L;
   ZIO *Z;
-  Mbuffer *b;
   const char *name;
 } LoadState;
 
@@ -86,17 +85,28 @@ static lua_Integer LoadInteger (LoadState *S) {
 }
 
 
-static TString *LoadString (LoadState *S) {
+static TString *LoadString (LoadState *S, Proto *p) {
+  lua_State *L = S->L;
   size_t size = LoadByte(S);
+  TString *ts;
   if (size == 0xFF)
     LoadVar(S, size);
   if (size == 0)
     return NULL;
-  else {
-    char *s = luaZ_openspace(S->L, S->b, --size);
-    LoadVector(S, s, size);
-    return luaS_newlstr(S->L, s, size);
+  else if (--size <= LUAI_MAXSHORTLEN) {  /* short string? */
+    char buff[LUAI_MAXSHORTLEN];
+    LoadVector(S, buff, size);
+    ts = luaS_newlstr(L, buff, size);
   }
+  else {  /* long string */
+    ts = luaS_createlngstrobj(L, size);
+    setsvalue2s(L, L->top, ts);  /* anchor it ('loadVector' can GC) */
+    luaD_inctop(L);
+    LoadVector(S, getstr(ts), size);  /* load directly in final place */
+    L->top--;  /* pop string */
+  }
+  luaC_objbarrier(L, p, ts);
+  return ts;
 }
 
 
@@ -136,7 +146,7 @@ static void LoadConstants (LoadState *S, Proto *f) {
       break;
     case LUA_TSHRSTR:
     case LUA_TLNGSTR:
-      setsvalue2n(S->L, o, LoadString(S));
+      setsvalue2n(S->L, o, LoadString(S, f));
       break;
     default:
       lua_assert(0);
@@ -154,6 +164,7 @@ static void LoadProtos (LoadState *S, Proto *f) {
     f->p[i] = NULL;
   for (i = 0; i < n; i++) {
     f->p[i] = luaF_newproto(S->L);
+    luaC_objbarrier(S->L, f, f->p[i]);
     LoadFunction(S, f->p[i], f->source);
   }
 }
@@ -185,18 +196,18 @@ static void LoadDebug (LoadState *S, Proto *f) {
   for (i = 0; i < n; i++)
     f->locvars[i].varname = NULL;
   for (i = 0; i < n; i++) {
-    f->locvars[i].varname = LoadString(S);
+    f->locvars[i].varname = LoadString(S, f);
     f->locvars[i].startpc = LoadInt(S);
     f->locvars[i].endpc = LoadInt(S);
   }
   n = LoadInt(S);
   for (i = 0; i < n; i++)
-    f->upvalues[i].name = LoadString(S);
+    f->upvalues[i].name = LoadString(S, f);
 }
 
 
 static void LoadFunction (LoadState *S, Proto *f, TString *psource) {
-  f->source = LoadString(S);
+  f->source = LoadString(S, f);
   if (f->source == NULL)  /* no source in dump? */
     f->source = psource;  /* reuse parent's source */
   f->linedefined = LoadInt(S);
@@ -251,8 +262,7 @@ static void checkHeader (LoadState *S) {
 /*
 ** load precompiled chunk
 */
-LClosure *luaU_undump(lua_State *L, ZIO *Z, Mbuffer *buff,
-                      const char *name) {
+LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
   LoadState S;
   LClosure *cl;
   if (*name == '@' || *name == '=')
@@ -263,12 +273,12 @@ LClosure *luaU_undump(lua_State *L, ZIO *Z, Mbuffer *buff,
     S.name = name;
   S.L = L;
   S.Z = Z;
-  S.b = buff;
   checkHeader(&S);
   cl = luaF_newLclosure(L, LoadByte(&S));
   setclLvalue(L, L->top, cl);
-  incr_top(L);
+  luaD_inctop(L);
   cl->p = luaF_newproto(L);
+  luaC_objbarrier(L, cl, cl->p);
   LoadFunction(&S, cl->p, NULL);
   lua_assert(cl->nupvalues == cl->p->sizeupvalues);
   luai_verifycode(L, buff, cl->p);
diff --git a/source/extern/lua/lundump.h b/source/extern/lua/lundump.h
index ef43d51..ce492d6 100644
--- a/source/extern/lua/lundump.h
+++ b/source/extern/lua/lundump.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lundump.h,v 1.44 2014/06/19 18:27:20 roberto Exp $
+** $Id: lundump.h,v 1.45.1.1 2017/04/19 17:20:42 roberto Exp $
 ** load precompiled Lua chunks
 ** See Copyright Notice in lua.h
 */
@@ -23,8 +23,7 @@
 #define LUAC_FORMAT	0	/* this is the official format */
 
 /* load one chunk; from lundump.c */
-LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff,
-                                 const char* name);
+LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, const char* name);
 
 /* dump one chunk; from ldump.c */
 LUAI_FUNC int luaU_dump (lua_State* L, const Proto* f, lua_Writer w,
diff --git a/source/extern/lua/lutf8lib.c b/source/extern/lua/lutf8lib.c
index 9042582..10bd238 100644
--- a/source/extern/lua/lutf8lib.c
+++ b/source/extern/lua/lutf8lib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lutf8lib.c,v 1.15 2015/03/28 19:16:55 roberto Exp $
+** $Id: lutf8lib.c,v 1.16.1.1 2017/04/19 17:29:57 roberto Exp $
 ** Standard library for UTF-8 manipulation
 ** See Copyright Notice in lua.h
 */
@@ -171,7 +171,7 @@ static int byteoffset (lua_State *L) {
   }
   else {
     if (iscont(s + posi))
-      luaL_error(L, "initial position is a continuation byte");
+      return luaL_error(L, "initial position is a continuation byte");
     if (n < 0) {
        while (n < 0 && posi > 0) {  /* move back */
          do {  /* find beginning of previous character */
@@ -194,7 +194,7 @@ static int byteoffset (lua_State *L) {
     lua_pushinteger(L, posi + 1);
   else  /* no such character */
     lua_pushnil(L);
-  return 1;  
+  return 1;
 }
 
 
diff --git a/source/extern/lua/lvm.c b/source/extern/lua/lvm.c
index a8cefc5..cc43d87 100644
--- a/source/extern/lua/lvm.c
+++ b/source/extern/lua/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.245 2015/06/09 15:53:35 roberto Exp $
+** $Id: lvm.c,v 2.268.1.1 2017/04/19 17:39:34 roberto Exp $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -153,75 +153,88 @@ static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
 
 
 /*
-** Main function for table access (invoking metamethods if needed).
-** Compute 'val = t[key]'
+** Finish the table access 'val = t[key]'.
+** if 'slot' is NULL, 't' is not a table; otherwise, 'slot' points to
+** t[k] entry (which must be nil).
 */
-void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
+void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
+                      const TValue *slot) {
   int loop;  /* counter to avoid infinite loops */
+  const TValue *tm;  /* metamethod */
   for (loop = 0; loop < MAXTAGLOOP; loop++) {
-    const TValue *tm;
-    if (ttistable(t)) {  /* 't' is a table? */
-      Table *h = hvalue(t);
-      const TValue *res = luaH_get(h, key); /* do a primitive get */
-      if (!ttisnil(res) ||  /* result is not nil? */
-          (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
-        setobj2s(L, val, res);  /* result is the raw get */
+    if (slot == NULL) {  /* 't' is not a table? */
+      lua_assert(!ttistable(t));
+      tm = luaT_gettmbyobj(L, t, TM_INDEX);
+      if (ttisnil(tm))
+        luaG_typeerror(L, t, "index");  /* no metamethod */
+      /* else will try the metamethod */
+    }
+    else {  /* 't' is a table */
+      lua_assert(ttisnil(slot));
+      tm = fasttm(L, hvalue(t)->metatable, TM_INDEX);  /* table's metamethod */
+      if (tm == NULL) {  /* no metamethod? */
+        setnilvalue(val);  /* result is nil */
         return;
       }
-      /* else will try metamethod */
+      /* else will try the metamethod */
     }
-    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
-      luaG_typeerror(L, t, "index");  /* no metamethod */
-    if (ttisfunction(tm)) {  /* metamethod is a function */
-      luaT_callTM(L, tm, t, key, val, 1);
+    if (ttisfunction(tm)) {  /* is metamethod a function? */
+      luaT_callTM(L, tm, t, key, val, 1);  /* call it */
       return;
     }
-    t = tm;  /* else repeat access over 'tm' */
+    t = tm;  /* else try to access 'tm[key]' */
+    if (luaV_fastget(L,t,key,slot,luaH_get)) {  /* fast track? */
+      setobj2s(L, val, slot);  /* done */
+      return;
+    }
+    /* else repeat (tail call 'luaV_finishget') */
   }
-  luaG_runerror(L, "gettable chain too long; possible loop");
+  luaG_runerror(L, "'__index' chain too long; possible loop");
 }
 
 
 /*
-** Main function for table assignment (invoking metamethods if needed).
-** Compute 't[key] = val'
+** Finish a table assignment 't[key] = val'.
+** If 'slot' is NULL, 't' is not a table.  Otherwise, 'slot' points
+** to the entry 't[key]', or to 'luaO_nilobject' if there is no such
+** entry.  (The value at 'slot' must be nil, otherwise 'luaV_fastset'
+** would have done the job.)
 */
-void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
+void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
+                     StkId val, const TValue *slot) {
   int loop;  /* counter to avoid infinite loops */
   for (loop = 0; loop < MAXTAGLOOP; loop++) {
-    const TValue *tm;
-    if (ttistable(t)) {  /* 't' is a table? */
-      Table *h = hvalue(t);
-      TValue *oldval = cast(TValue *, luaH_get(h, key));
-      /* if previous value is not nil, there must be a previous entry
-         in the table; a metamethod has no relevance */
-      if (!ttisnil(oldval) ||
-         /* previous value is nil; must check the metamethod */
-         ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
-         /* no metamethod; is there a previous entry in the table? */
-         (oldval != luaO_nilobject ||
-         /* no previous entry; must create one. (The next test is
-            always true; we only need the assignment.) */
-         (oldval = luaH_newkey(L, h, key), 1)))) {
+    const TValue *tm;  /* '__newindex' metamethod */
+    if (slot != NULL) {  /* is 't' a table? */
+      Table *h = hvalue(t);  /* save 't' table */
+      lua_assert(ttisnil(slot));  /* old value must be nil */
+      tm = fasttm(L, h->metatable, TM_NEWINDEX);  /* get metamethod */
+      if (tm == NULL) {  /* no metamethod? */
+        if (slot == luaO_nilobject)  /* no previous entry? */
+          slot = luaH_newkey(L, h, key);  /* create one */
         /* no metamethod and (now) there is an entry with given key */
-        setobj2t(L, oldval, val);  /* assign new value to that entry */
+        setobj2t(L, cast(TValue *, slot), val);  /* set its new value */
         invalidateTMcache(h);
         luaC_barrierback(L, h, val);
         return;
       }
       /* else will try the metamethod */
     }
-    else  /* not a table; check metamethod */
+    else {  /* not a table; check metamethod */
       if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
         luaG_typeerror(L, t, "index");
+    }
     /* try the metamethod */
     if (ttisfunction(tm)) {
       luaT_callTM(L, tm, t, key, val, 0);
       return;
     }
     t = tm;  /* else repeat assignment over 'tm' */
+    if (luaV_fastset(L, t, key, slot, luaH_get, val))
+      return;  /* done */
+    /* else loop */
   }
-  luaG_runerror(L, "settable chain too long; possible loop");
+  luaG_runerror(L, "'__newindex' chain too long; possible loop");
 }
 
 
@@ -443,6 +456,17 @@ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
 
 #define isemptystr(o)	(ttisshrstring(o) && tsvalue(o)->shrlen == 0)
 
+/* copy strings in stack from top - n up to top - 1 to buffer */
+static void copy2buff (StkId top, int n, char *buff) {
+  size_t tl = 0;  /* size already copied */
+  do {
+    size_t l = vslen(top - n);  /* length of string being copied */
+    memcpy(buff + tl, svalue(top - n), l * sizeof(char));
+    tl += l;
+  } while (--n > 0);
+}
+
+
 /*
 ** Main operation for concatenation: concat 'total' values in the stack,
 ** from 'L->top - total' up to 'L->top - 1'.
@@ -462,24 +486,24 @@ void luaV_concat (lua_State *L, int total) {
     else {
       /* at least two non-empty string values; get as many as possible */
       size_t tl = vslen(top - 1);
-      char *buffer;
-      int i;
-      /* collect total length */
-      for (i = 1; i < total && tostring(L, top-i-1); i++) {
-        size_t l = vslen(top - i - 1);
+      TString *ts;
+      /* collect total length and number of strings */
+      for (n = 1; n < total && tostring(L, top - n - 1); n++) {
+        size_t l = vslen(top - n - 1);
         if (l >= (MAX_SIZE/sizeof(char)) - tl)
           luaG_runerror(L, "string length overflow");
         tl += l;
       }
-      buffer = luaZ_openspace(L, &G(L)->buff, tl);
-      tl = 0;
-      n = i;
-      do {  /* copy all strings to buffer */
-        size_t l = vslen(top - i);
-        memcpy(buffer+tl, svalue(top-i), l * sizeof(char));
-        tl += l;
-      } while (--i > 0);
-      setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));  /* create result */
+      if (tl <= LUAI_MAXSHORTLEN) {  /* is result a short string? */
+        char buff[LUAI_MAXSHORTLEN];
+        copy2buff(top, n, buff);  /* copy strings to buffer */
+        ts = luaS_newlstr(L, buff, tl);
+      }
+      else {  /* long string; copy strings directly to final result */
+        ts = luaS_createlngstrobj(L, tl);
+        copy2buff(top, n, getstr(ts));
+      }
+      setsvalue2s(L, top - n, ts);  /* create result */
     }
     total -= n-1;  /* got 'n' strings to create 1 new */
     L->top -= n-1;  /* popped 'n' strings and pushed one */
@@ -700,27 +724,20 @@ void luaV_finishOp (lua_State *L) {
 ** some macros for common tasks in 'luaV_execute'
 */
 
-#if !defined(luai_runtimecheck)
-#define luai_runtimecheck(L, c)		/* void */
-#endif
-
 
 #define RA(i)	(base+GETARG_A(i))
-/* to be used after possible stack reallocation */
 #define RB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
 #define RC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
 #define RKB(i)	check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
 	ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
 #define RKC(i)	check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
 	ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
-#define KBx(i)  \
-  (k + (GETARG_Bx(i) != 0 ? GETARG_Bx(i) - 1 : GETARG_Ax(*ci->u.l.savedpc++)))
 
 
 /* execute a jump instruction */
 #define dojump(ci,i,e) \
   { int a = GETARG_A(i); \
-    if (a > 0) luaF_close(L, ci->u.l.base + a - 1); \
+    if (a != 0) luaF_close(L, ci->u.l.base + a - 1); \
     ci->u.l.savedpc += GETARG_sBx(i) + e; }
 
 /* for test instructions, execute the jump instruction that follows it */
@@ -730,38 +747,58 @@ void luaV_finishOp (lua_State *L) {
 #define Protect(x)	{ {x;}; base = ci->u.l.base; }
 
 #define checkGC(L,c)  \
-  Protect( luaC_condGC(L,{L->top = (c);  /* limit of live values */ \
-                          luaC_step(L); \
-                          L->top = ci->top;})  /* restore top */ \
-           luai_threadyield(L); )
+	{ luaC_condGC(L, L->top = (c),  /* limit of live values */ \
+                         Protect(L->top = ci->top));  /* restore top */ \
+           luai_threadyield(L); }
 
 
+/* fetch an instruction and prepare its execution */
+#define vmfetch()	{ \
+  i = *(ci->u.l.savedpc++); \
+  if (L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) \
+    Protect(luaG_traceexec(L)); \
+  ra = RA(i); /* WARNING: any stack reallocation invalidates 'ra' */ \
+  lua_assert(base == ci->u.l.base); \
+  lua_assert(base <= L->top && L->top < L->stack + L->stacksize); \
+}
+
 #define vmdispatch(o)	switch(o)
 #define vmcase(l)	case l:
 #define vmbreak		break
 
+
+/*
+** copy of 'luaV_gettable', but protecting the call to potential
+** metamethod (which can reallocate the stack)
+*/
+#define gettableProtected(L,t,k,v)  { const TValue *slot; \
+  if (luaV_fastget(L,t,k,slot,luaH_get)) { setobj2s(L, v, slot); } \
+  else Protect(luaV_finishget(L,t,k,v,slot)); }
+
+
+/* same for 'luaV_settable' */
+#define settableProtected(L,t,k,v) { const TValue *slot; \
+  if (!luaV_fastset(L,t,k,slot,luaH_get,v)) \
+    Protect(luaV_finishset(L,t,k,v,slot)); }
+
+
+
 void luaV_execute (lua_State *L) {
   CallInfo *ci = L->ci;
   LClosure *cl;
   TValue *k;
   StkId base;
+  ci->callstatus |= CIST_FRESH;  /* fresh invocation of 'luaV_execute" */
  newframe:  /* reentry point when frame changes (call/return) */
   lua_assert(ci == L->ci);
-  cl = clLvalue(ci->func);
-  k = cl->p->k;
-  base = ci->u.l.base;
+  cl = clLvalue(ci->func);  /* local reference to function's closure */
+  k = cl->p->k;  /* local reference to function's constant table */
+  base = ci->u.l.base;  /* local copy of function's base */
   /* main loop of interpreter */
   for (;;) {
-    Instruction i = *(ci->u.l.savedpc++);
+    Instruction i;
     StkId ra;
-    if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
-        (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
-      Protect(luaG_traceexec(L));
-    }
-    /* WARNING: several calls may realloc the stack and invalidate 'ra' */
-    ra = RA(i);
-    lua_assert(base == ci->u.l.base);
-    lua_assert(base <= L->top && L->top < L->stack + L->stacksize);
+    vmfetch();
     vmdispatch (GET_OPCODE(i)) {
       vmcase(OP_MOVE) {
         setobjs2s(L, ra, RB(i));
@@ -797,17 +834,22 @@ void luaV_execute (lua_State *L) {
         vmbreak;
       }
       vmcase(OP_GETTABUP) {
-        int b = GETARG_B(i);
-        Protect(luaV_gettable(L, cl->upvals[b]->v, RKC(i), ra));
+        TValue *upval = cl->upvals[GETARG_B(i)]->v;
+        TValue *rc = RKC(i);
+        gettableProtected(L, upval, rc, ra);
         vmbreak;
       }
       vmcase(OP_GETTABLE) {
-        Protect(luaV_gettable(L, RB(i), RKC(i), ra));
+        StkId rb = RB(i);
+        TValue *rc = RKC(i);
+        gettableProtected(L, rb, rc, ra);
         vmbreak;
       }
       vmcase(OP_SETTABUP) {
-        int a = GETARG_A(i);
-        Protect(luaV_settable(L, cl->upvals[a]->v, RKB(i), RKC(i)));
+        TValue *upval = cl->upvals[GETARG_A(i)]->v;
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        settableProtected(L, upval, rb, rc);
         vmbreak;
       }
       vmcase(OP_SETUPVAL) {
@@ -817,7 +859,9 @@ void luaV_execute (lua_State *L) {
         vmbreak;
       }
       vmcase(OP_SETTABLE) {
-        Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
+        TValue *rb = RKB(i);
+        TValue *rc = RKC(i);
+        settableProtected(L, ra, rb, rc);
         vmbreak;
       }
       vmcase(OP_NEWTABLE) {
@@ -831,9 +875,15 @@ void luaV_execute (lua_State *L) {
         vmbreak;
       }
       vmcase(OP_SELF) {
+        const TValue *aux;
         StkId rb = RB(i);
-        setobjs2s(L, ra+1, rb);
-        Protect(luaV_gettable(L, rb, RKC(i), ra));
+        TValue *rc = RKC(i);
+        TString *key = tsvalue(rc);  /* key must be a string */
+        setobjs2s(L, ra + 1, rb);
+        if (luaV_fastget(L, rb, key, aux, luaH_getstr)) {
+          setobj2s(L, ra, aux);
+        }
+        else Protect(luaV_finishget(L, rb, rc, ra, aux));
         vmbreak;
       }
       vmcase(OP_ADD) {
@@ -1020,7 +1070,7 @@ void luaV_execute (lua_State *L) {
         StkId rb;
         L->top = base + c + 1;  /* mark the end of concat operands */
         Protect(luaV_concat(L, c - b + 1));
-        ra = RA(i);  /* 'luav_concat' may invoke TMs and move the stack */
+        ra = RA(i);  /* 'luaV_concat' may invoke TMs and move the stack */
         rb = base + b;
         setobjs2s(L, ra, rb);
         checkGC(L, (ra >= rb ? ra + 1 : rb));
@@ -1035,7 +1085,7 @@ void luaV_execute (lua_State *L) {
         TValue *rb = RKB(i);
         TValue *rc = RKC(i);
         Protect(
-          if (cast_int(luaV_equalobj(L, rb, rc)) != GETARG_A(i))
+          if (luaV_equalobj(L, rb, rc) != GETARG_A(i))
             ci->u.l.savedpc++;
           else
             donextjump(ci);
@@ -1082,12 +1132,12 @@ void luaV_execute (lua_State *L) {
         int nresults = GETARG_C(i) - 1;
         if (b != 0) L->top = ra+b;  /* else previous instruction set top */
         if (luaD_precall(L, ra, nresults)) {  /* C function? */
-          if (nresults >= 0) L->top = ci->top;  /* adjust results */
-          base = ci->u.l.base;
+          if (nresults >= 0)
+            L->top = ci->top;  /* adjust results */
+          Protect((void)0);  /* update 'base' */
         }
         else {  /* Lua function */
           ci = L->ci;
-          ci->callstatus |= CIST_REENTRY;
           goto newframe;  /* restart luaV_execute over new Lua function */
         }
         vmbreak;
@@ -1096,8 +1146,9 @@ void luaV_execute (lua_State *L) {
         int b = GETARG_B(i);
         if (b != 0) L->top = ra+b;  /* else previous instruction set top */
         lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
-        if (luaD_precall(L, ra, LUA_MULTRET))  /* C function? */
-          base = ci->u.l.base;
+        if (luaD_precall(L, ra, LUA_MULTRET)) {  /* C function? */
+          Protect((void)0);  /* update 'base' */
+        }
         else {
           /* tail call: put called frame (n) in place of caller one (o) */
           CallInfo *nci = L->ci;  /* called frame */
@@ -1125,8 +1176,8 @@ void luaV_execute (lua_State *L) {
       vmcase(OP_RETURN) {
         int b = GETARG_B(i);
         if (cl->p->sizep > 0) luaF_close(L, base);
-        b = luaD_poscall(L, ra, (b != 0 ? b - 1 : L->top - ra));
-        if (!(ci->callstatus & CIST_REENTRY))  /* 'ci' still the called one */
+        b = luaD_poscall(L, ci, ra, (b != 0 ? b - 1 : cast_int(L->top - ra)));
+        if (ci->callstatus & CIST_FRESH)  /* local 'ci' still from callee */
           return;  /* external invocation: return */
         else {  /* invocation via reentry: continue execution */
           ci = L->ci;
@@ -1139,7 +1190,7 @@ void luaV_execute (lua_State *L) {
       vmcase(OP_FORLOOP) {
         if (ttisinteger(ra)) {  /* integer loop? */
           lua_Integer step = ivalue(ra + 2);
-          lua_Integer idx = ivalue(ra) + step; /* increment index */
+          lua_Integer idx = intop(+, ivalue(ra), step); /* increment index */
           lua_Integer limit = ivalue(ra + 1);
           if ((0 < step) ? (idx <= limit) : (limit <= idx)) {
             ci->u.l.savedpc += GETARG_sBx(i);  /* jump back */
@@ -1171,7 +1222,7 @@ void luaV_execute (lua_State *L) {
           /* all values are integer */
           lua_Integer initv = (stopnow ? 0 : ivalue(init));
           setivalue(plimit, ilimit);
-          setivalue(init, initv - ivalue(pstep));
+          setivalue(init, intop(-, initv, ivalue(pstep)));
         }
         else {  /* try making all values floats */
           lua_Number ninit; lua_Number nlimit; lua_Number nstep;
@@ -1194,7 +1245,7 @@ void luaV_execute (lua_State *L) {
         setobjs2s(L, cb+1, ra+1);
         setobjs2s(L, cb, ra);
         L->top = cb + 3;  /* func. + 2 args (state and index) */
-        Protect(luaD_call(L, cb, GETARG_C(i), 1));
+        Protect(luaD_call(L, cb, GETARG_C(i)));
         L->top = ci->top;
         i = *(ci->u.l.savedpc++);  /* go to next instruction */
         ra = RA(i);
@@ -1219,11 +1270,10 @@ void luaV_execute (lua_State *L) {
           lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
           c = GETARG_Ax(*ci->u.l.savedpc++);
         }
-        luai_runtimecheck(L, ttistable(ra));
         h = hvalue(ra);
         last = ((c-1)*LFIELDS_PER_FLUSH) + n;
         if (last > h->sizearray)  /* needs more space? */
-          luaH_resizearray(L, h, last);  /* pre-allocate it at once */
+          luaH_resizearray(L, h, last);  /* preallocate it at once */
         for (; n > 0; n--) {
           TValue *val = ra+n;
           luaH_setint(L, h, last--, val);
@@ -1243,23 +1293,21 @@ void luaV_execute (lua_State *L) {
         vmbreak;
       }
       vmcase(OP_VARARG) {
-        int b = GETARG_B(i) - 1;
+        int b = GETARG_B(i) - 1;  /* required results */
         int j;
         int n = cast_int(base - ci->func) - cl->p->numparams - 1;
+        if (n < 0)  /* less arguments than parameters? */
+          n = 0;  /* no vararg arguments */
         if (b < 0) {  /* B == 0? */
           b = n;  /* get all var. arguments */
           Protect(luaD_checkstack(L, n));
           ra = RA(i);  /* previous call may change the stack */
           L->top = ra + n;
         }
-        for (j = 0; j < b; j++) {
-          if (j < n) {
-            setobjs2s(L, ra + j, base - n + j);
-          }
-          else {
-            setnilvalue(ra + j);
-          }
-        }
+        for (j = 0; j < b && j < n; j++)
+          setobjs2s(L, ra + j, base - n + j);
+        for (; j < b; j++)  /* complete required results with nil */
+          setnilvalue(ra + j);
         vmbreak;
       }
       vmcase(OP_EXTRAARG) {
diff --git a/source/extern/lua/lvm.h b/source/extern/lua/lvm.h
index 0613826..a8f954f 100644
--- a/source/extern/lua/lvm.h
+++ b/source/extern/lua/lvm.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.h,v 2.35 2015/02/20 14:27:53 roberto Exp $
+** $Id: lvm.h,v 2.41.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -48,15 +48,60 @@
 #define luaV_rawequalobj(t1,t2)		luaV_equalobj(NULL,t1,t2)
 
 
+/*
+** fast track for 'gettable': if 't' is a table and 't[k]' is not nil,
+** return 1 with 'slot' pointing to 't[k]' (final result).  Otherwise,
+** return 0 (meaning it will have to check metamethod) with 'slot'
+** pointing to a nil 't[k]' (if 't' is a table) or NULL (otherwise).
+** 'f' is the raw get function to use.
+*/
+#define luaV_fastget(L,t,k,slot,f) \
+  (!ttistable(t)  \
+   ? (slot = NULL, 0)  /* not a table; 'slot' is NULL and result is 0 */  \
+   : (slot = f(hvalue(t), k),  /* else, do raw access */  \
+      !ttisnil(slot)))  /* result not nil? */
+
+/*
+** standard implementation for 'gettable'
+*/
+#define luaV_gettable(L,t,k,v) { const TValue *slot; \
+  if (luaV_fastget(L,t,k,slot,luaH_get)) { setobj2s(L, v, slot); } \
+  else luaV_finishget(L,t,k,v,slot); }
+
+
+/*
+** Fast track for set table. If 't' is a table and 't[k]' is not nil,
+** call GC barrier, do a raw 't[k]=v', and return true; otherwise,
+** return false with 'slot' equal to NULL (if 't' is not a table) or
+** 'nil'. (This is needed by 'luaV_finishget'.) Note that, if the macro
+** returns true, there is no need to 'invalidateTMcache', because the
+** call is not creating a new entry.
+*/
+#define luaV_fastset(L,t,k,slot,f,v) \
+  (!ttistable(t) \
+   ? (slot = NULL, 0) \
+   : (slot = f(hvalue(t), k), \
+     ttisnil(slot) ? 0 \
+     : (luaC_barrierback(L, hvalue(t), v), \
+        setobj2t(L, cast(TValue *,slot), v), \
+        1)))
+
+
+#define luaV_settable(L,t,k,v) { const TValue *slot; \
+  if (!luaV_fastset(L,t,k,slot,luaH_get,v)) \
+    luaV_finishset(L,t,k,v,slot); }
+
+
+
 LUAI_FUNC int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2);
 LUAI_FUNC int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r);
 LUAI_FUNC int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r);
 LUAI_FUNC int luaV_tonumber_ (const TValue *obj, lua_Number *n);
 LUAI_FUNC int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode);
-LUAI_FUNC void luaV_gettable (lua_State *L, const TValue *t, TValue *key,
-                                            StkId val);
-LUAI_FUNC void luaV_settable (lua_State *L, const TValue *t, TValue *key,
-                                            StkId val);
+LUAI_FUNC void luaV_finishget (lua_State *L, const TValue *t, TValue *key,
+                               StkId val, const TValue *slot);
+LUAI_FUNC void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
+                               StkId val, const TValue *slot);
 LUAI_FUNC void luaV_finishOp (lua_State *L);
 LUAI_FUNC void luaV_execute (lua_State *L);
 LUAI_FUNC void luaV_concat (lua_State *L, int total);
diff --git a/source/extern/lua/lzio.c b/source/extern/lua/lzio.c
index 4649392..6f79094 100644
--- a/source/extern/lua/lzio.c
+++ b/source/extern/lua/lzio.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lzio.c,v 1.36 2014/11/02 19:19:04 roberto Exp $
+** $Id: lzio.c,v 1.37.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Buffered streams
 ** See Copyright Notice in lua.h
 */
@@ -66,13 +66,3 @@ size_t luaZ_read (ZIO *z, void *b, size_t n) {
   return 0;
 }
 
-/* ------------------------------------------------------------------------ */
-char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) {
-  if (n > buff->buffsize) {
-    if (n < LUA_MINBUFFER) n = LUA_MINBUFFER;
-    luaZ_resizebuffer(L, buff, n);
-  }
-  return buff->buffer;
-}
-
-
diff --git a/source/extern/lua/lzio.h b/source/extern/lua/lzio.h
index b2e56bc..d897870 100644
--- a/source/extern/lua/lzio.h
+++ b/source/extern/lua/lzio.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lzio.h,v 1.30 2014/12/19 17:26:14 roberto Exp $
+** $Id: lzio.h,v 1.31.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Buffered streams
 ** See Copyright Notice in lua.h
 */
@@ -44,7 +44,6 @@ typedef struct Mbuffer {
 #define luaZ_freebuffer(L, buff)	luaZ_resizebuffer(L, buff, 0)
 
 
-LUAI_FUNC char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n);
 LUAI_FUNC void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader,
                                         void *data);
 LUAI_FUNC size_t luaZ_read (ZIO* z, void *b, size_t n);	/* read next n bytes */
diff --git a/source/extern/luaconf.h b/source/extern/luaconf.h
index 7cfa4fa..9eeeea6 100644
--- a/source/extern/luaconf.h
+++ b/source/extern/luaconf.h
@@ -1,5 +1,5 @@
 /*
-** $Id: luaconf.h,v 1.251 2015/05/20 17:39:23 roberto Exp $
+** $Id: luaconf.h,v 1.259.1.1 2017/04/19 17:29:57 roberto Exp $
 ** Configuration file for Lua
 ** See Copyright Notice in lua.h
 */
@@ -145,7 +145,7 @@
 
 #if !defined(LUA_FLOAT_TYPE)
 #define LUA_FLOAT_TYPE	LUA_FLOAT_DOUBLE
-#endif								/* } */
+#endif
 
 /* }================================================================== */
 
@@ -158,6 +158,18 @@
 ** ===================================================================
 */
 
+/*
+** LUA_PATH_SEP is the character that separates templates in a path.
+** LUA_PATH_MARK is the string that marks the substitution points in a
+** template.
+** LUA_EXEC_DIR in a Windows path is replaced by the executable's
+** directory.
+*/
+#define LUA_PATH_SEP            ";"
+#define LUA_PATH_MARK           "?"
+#define LUA_EXEC_DIR            "!"
+
+
 /*
 @@ LUA_PATH_DEFAULT is the default path that Lua uses to look for
 ** Lua libraries.
@@ -404,7 +416,7 @@
 
 /*
 @@ LUA_NUMBER is the floating-point type used by Lua.
-@@ LUAI_UACNUMBER is the result of an 'usual argument conversion'
+@@ LUAI_UACNUMBER is the result of a 'default argument promotion'
 @@ over a floating number.
 @@ l_mathlim(x) corrects limit name 'x' to the proper float type
 ** by prefixing it with one of FLT/DBL/LDBL.
@@ -412,9 +424,34 @@
 @@ LUA_NUMBER_FMT is the format for writing floats.
 @@ lua_number2str converts a float to a string.
 @@ l_mathop allows the addition of an 'l' or 'f' to all math operations.
+@@ l_floor takes the floor of a float.
 @@ lua_str2number converts a decimal numeric string to a number.
 */
 
+
+/* The following definitions are good for most cases here */
+
+#define l_floor(x)		(l_mathop(floor)(x))
+
+#define lua_number2str(s,sz,n)  \
+	l_sprintf((s), sz, LUA_NUMBER_FMT, (LUAI_UACNUMBER)(n))
+
+/*
+@@ lua_numbertointeger converts a float number to an integer, or
+** returns 0 if float is not within the range of a lua_Integer.
+** (The range comparisons are tricky because of rounding. The tests
+** here assume a two-complement representation, where MININTEGER always
+** has an exact representation as a float; MAXINTEGER may not have one,
+** and therefore its conversion to float may have an ill-defined value.)
+*/
+#define lua_numbertointeger(n,p) \
+  ((n) >= (LUA_NUMBER)(LUA_MININTEGER) && \
+   (n) < -(LUA_NUMBER)(LUA_MININTEGER) && \
+      (*(p) = (LUA_INTEGER)(n), 1))
+
+
+/* now the variable definitions */
+
 #if LUA_FLOAT_TYPE == LUA_FLOAT_FLOAT		/* { single float */
 
 #define LUA_NUMBER	float
@@ -468,32 +505,13 @@
 #endif					/* } */
 
 
-#define l_floor(x)		(l_mathop(floor)(x))
-
-#define lua_number2str(s,n)	sprintf((s), LUA_NUMBER_FMT, (n))
-
-
-/*
-@@ lua_numbertointeger converts a float number to an integer, or
-** returns 0 if float is not within the range of a lua_Integer.
-** (The range comparisons are tricky because of rounding. The tests
-** here assume a two-complement representation, where MININTEGER always
-** has an exact representation as a float; MAXINTEGER may not have one,
-** and therefore its conversion to float may have an ill-defined value.)
-*/
-#define lua_numbertointeger(n,p) \
-  ((n) >= (LUA_NUMBER)(LUA_MININTEGER) && \
-   (n) < -(LUA_NUMBER)(LUA_MININTEGER) && \
-      (*(p) = (LUA_INTEGER)(n), 1))
-
-
 
 /*
 @@ LUA_INTEGER is the integer type used by Lua.
 **
 @@ LUA_UNSIGNED is the unsigned version of LUA_INTEGER.
 **
-@@ LUAI_UACINT is the result of an 'usual argument conversion'
+@@ LUAI_UACINT is the result of a 'default argument promotion'
 @@ over a lUA_INTEGER.
 @@ LUA_INTEGER_FRMLEN is the length modifier for reading/writing integers.
 @@ LUA_INTEGER_FMT is the format for writing integers.
@@ -506,10 +524,12 @@
 /* The following definitions are good for most cases here */
 
 #define LUA_INTEGER_FMT		"%" LUA_INTEGER_FRMLEN "d"
-#define lua_integer2str(s,n)	sprintf((s), LUA_INTEGER_FMT, (n))
 
 #define LUAI_UACINT		LUA_INTEGER
 
+#define lua_integer2str(s,sz,n)  \
+	l_sprintf((s), sz, LUA_INTEGER_FMT, (LUAI_UACINT)(n))
+
 /*
 ** use LUAI_UACINT here to avoid problems with promotions (which
 ** can turn a comparison between unsigneds into a signed comparison)
@@ -537,6 +557,7 @@
 
 #elif LUA_INT_TYPE == LUA_INT_LONGLONG	/* }{ long long */
 
+/* use presence of macro LLONG_MAX as proxy for C99 compliance */
 #if defined(LLONG_MAX)		/* { */
 /* use ISO C99 stuff */
 
@@ -577,6 +598,17 @@
 ** ===================================================================
 */
 
+/*
+@@ l_sprintf is equivalent to 'snprintf' or 'sprintf' in C89.
+** (All uses in Lua have only one format item.)
+*/
+#if !defined(LUA_USE_C89)
+#define l_sprintf(s,sz,f,i)	snprintf(s,sz,f,i)
+#else
+#define l_sprintf(s,sz,f,i)	((void)(sz), sprintf(s,f,i))
+#endif
+
+
 /*
 @@ lua_strx2number converts an hexadecimal numeric string to a number.
 ** In C99, 'strtod' does that conversion. Otherwise, you can
@@ -584,18 +616,26 @@
 ** implementation.
 */
 #if !defined(LUA_USE_C89)
-#define lua_strx2number(s,p)	lua_str2number(s,p)
+#define lua_strx2number(s,p)		lua_str2number(s,p)
 #endif
 
 
 /*
-@@ lua_number2strx converts a float to an hexadecimal numeric string. 
+@@ lua_pointer2str converts a pointer to a readable string in a
+** non-specified way.
+*/
+#define lua_pointer2str(buff,sz,p)	l_sprintf(buff,sz,"%p",p)
+
+
+/*
+@@ lua_number2strx converts a float to an hexadecimal numeric string.
 ** In C99, 'sprintf' (with format specifiers '%a'/'%A') does that.
 ** Otherwise, you can leave 'lua_number2strx' undefined and Lua will
 ** provide its own implementation.
 */
 #if !defined(LUA_USE_C89)
-#define lua_number2strx(L,b,f,n)	sprintf(b,f,n)
+#define lua_number2strx(L,b,sz,f,n)  \
+	((void)L, l_sprintf(b,sz,f,(LUAI_UACNUMBER)(n)))
 #endif
 
 
@@ -711,11 +751,11 @@
 /*
 @@ LUAL_BUFFERSIZE is the buffer size used by the lauxlib buffer system.
 ** CHANGE it if it uses too much C-stack space. (For long double,
-** 'string.format("%.99f", 1e4932)' needs ~5030 bytes, so a
+** 'string.format("%.99f", -1e4932)' needs 5034 bytes, so a
 ** smaller buffer would force a memory allocation for each call to
 ** 'string.format'.)
 */
-#if defined(LUA_FLOAT_LONGDOUBLE)
+#if LUA_FLOAT_TYPE == LUA_FLOAT_LONGDOUBLE
 #define LUAL_BUFFERSIZE		8192
 #else
 #define LUAL_BUFFERSIZE   ((int)(0x80 * sizeof(void*) * sizeof(lua_Integer)))
diff --git a/source/extern/lualib.h b/source/extern/lualib.h
index 5165c0f..f5304aa 100644
--- a/source/extern/lualib.h
+++ b/source/extern/lualib.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lualib.h,v 1.44 2014/02/06 17:32:33 roberto Exp $
+** $Id: lualib.h,v 1.45.1.1 2017/04/19 17:20:42 roberto Exp $
 ** Lua standard libraries
 ** See Copyright Notice in lua.h
 */
@@ -11,6 +11,9 @@
 #include "lua.h"
 
 
+/* version suffix for environment variable names */
+#define LUA_VERSUFFIX          "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
+
 
 LUAMOD_API int (luaopen_base) (lua_State *L);