Fix text box cursor offset with hidden text

assets/opensb/interface/windowconfig/multiplayer.config.patch

@@ -1,5 +1,6 @@
 {
   "password" : {
-    "hidden" : true
+    "hidden" : true,
+    "hAnchor" : "right"
   }
 }

source/windowing/StarGuiContext.cpp

@@ -385,6 +385,7 @@ int GuiContext::stringWidth(String const& s) {
   return textPainter()->stringWidth(s);
 }
 
+//TODO: Make this use StringView
 int GuiContext::stringInterfaceWidth(String const& s) {
   if (interfaceScale()) {
     // font size is already adjusted UP by interfaceScale, so we have to adjust

source/windowing/StarTextBoxWidget.cpp

@@ -102,15 +102,27 @@ int TextBoxWidget::getCursorOffset() { // horizontal only
     scale = 0.5;
   } else if (m_hAnchor == HorizontalAnchor::RightAnchor) {
     scale = -1.0;
+    if (m_textHidden) {
+      int width = context()->stringInterfaceWidth("*");
+      size_t chars = m_text.size();
+      return (width * chars) * scale + (width * (chars - m_cursorOffset));
+    } else {
       return context()->stringInterfaceWidth(m_text) * scale
            + context()->stringInterfaceWidth(m_text.substr(m_cursorOffset, m_text.size()));
+    }
   } else {
     throw GuiException("Somehow, the value of m_hAnchor became bad");
   }
 
+  if (m_textHidden) {
+    int width = context()->stringInterfaceWidth("*");
+    size_t chars = m_text.size();
+    return (int)std::ceil((width * chars) * scale - (width * (chars - m_cursorOffset)));
+  } else {
   return (int)std::ceil(context()->stringInterfaceWidth(m_text) * scale
                       - context()->stringInterfaceWidth(m_text.substr(m_cursorOffset, m_text.size())));
   }
+}
 
 void TextBoxWidget::update() {
   Widget::update();