partial fix [#30813] Small UI glitch with high DPI value in menus

fix provided by Julien Enche (trap).

also corrected some 2.4x theme colors (selected file, outliner and image background)

release/scripts/presets/interface_theme/blender_24x.xml

@@ -157,10 +157,10 @@
     </dopesheet_editor>
     <file_browser>
       <ThemeFileBrowser active_file="#828282"
-                        active_file_text="#fafafa"
+                        active_file_text="#ffffff"
                         scroll_handle="#7f7070"
                         scrollbar="#a0a0a0"
-                        selected_file="#7f7f7f"
+                        selected_file="#a0a0d0"
                         tiles="#b4b4b4">
         <space>
           <ThemeSpaceGeneric header="#b4b4b4"
@@ -173,7 +173,7 @@
                              text="#000000"
                              text_hi="#0f0f0f"
                              title="#000000"
-                             back="#b4b4b4">
+                             back="#808080">
           </ThemeSpaceGeneric>
         </space>
         <space_list>
@@ -262,7 +262,7 @@
                              text="#000000"
                              text_hi="#ffffff"
                              title="#000000"
-                             back="#757575">
+                             back="#353535">
           </ThemeSpaceGeneric>
         </space>
       </ThemeImageEditor>
@@ -381,7 +381,7 @@
                              text="#000000"
                              text_hi="#ffffff"
                              title="#000000"
-                             back="#b4b4b4">
+                             back="#999999">
           </ThemeSpaceGeneric>
         </space>
       </ThemeOutliner>

source/blender/editors/interface/interface_widgets.c

@@ -934,7 +934,7 @@ static void widget_draw_icon(uiBut *but, BIFIconID icon, float alpha, rcti *rect
 	}
 
 	if (ui_but_draw_menu_icon(but)) {
-		xs = rect->xmax - 17;
+		xs = rect->xmax - UI_DPI_ICON_SIZE - 1;
 		ys = (rect->ymin + rect->ymax - height) / 2;
 		
 		UI_icon_draw_aspect(xs, ys, ICON_RIGHTARROW_THIN, aspect, alpha);