Merge branch 'minor-pg-fixes'

Minor wxPropertyGrid fixes, notably fixing the expander buttons
appearance in high DPI under MSW.

See #24304.

samples/propgrid/propgrid.xrc

@@ -6,8 +6,8 @@
     <object class="wxBoxSizer">
         <object class="sizeritem">
             <option>1</option>
-            <flag>wxALL|wxEXPAND</flag>
-            <border>5</border>
+            <flag>wxEXPAND</flag>
+            <minsize>400,500</minsize>
             <object class="wxPropertyGridManager">
                 <style>wxPG_AUTO_SORT|wxPG_TOOLTIPS|wxPG_TOOLBAR</style>
                 <exstyle>wxPG_EX_MODE_BUTTONS|wxPG_EX_HELP_AS_TOOLTIPS</exstyle>

src/propgrid/propgrid.cpp

@@ -1308,6 +1308,11 @@ void wxPropertyGrid::CalculateFontAndBitmapStuff( int vspacing )
 
 #endif
 
+#ifdef wxPG_ICON_WIDTH
+    // Icons are always square in this case.
+    m_iconHeight = m_iconWidth;
+#endif
+
     m_gutterWidth = m_iconWidth / wxPG_GUTTER_DIV;
     if ( m_gutterWidth < wxPG_GUTTER_MIN )
         m_gutterWidth = wxPG_GUTTER_MIN;