server: Validate the parents every time we paint a window instead of only on RDW_UPDATENOW.

dlls/user32/painting.c

@@ -160,6 +160,9 @@ static BOOL redraw_window_rects( HWND hwnd, UINT flags, const RECT *rects, UINT
 {
     BOOL ret;
 
+    if (!(flags & (RDW_INVALIDATE|RDW_VALIDATE|RDW_INTERNALPAINT|RDW_NOINTERNALPAINT)))
+        return TRUE;  /* nothing to do */
+
     SERVER_START_REQ( redraw_window )
     {
         req->window = hwnd;

server/window.c

@@ -1051,7 +1051,7 @@ static void validate_children( struct window *win )
 }
 
 
-/* validate the update region of a window on all parents; helper for redraw_window */
+/* validate the update region of a window on all parents; helper for get_update_region */
 static void validate_parents( struct window *child )
 {
     int offset_x = 0, offset_y = 0;
@@ -1137,12 +1137,6 @@ static void redraw_window( struct window *win, struct region *region, int frame,
         inc_window_paint_count( win, -1 );
     }
 
-    if (flags & RDW_UPDATENOW)
-    {
-        validate_parents( win );
-        flags &= ~RDW_UPDATENOW;
-    }
-
     /* now process children recursively */
 
     if (flags & RDW_NOCHILDREN) return;
@@ -1982,6 +1976,7 @@ DECL_HANDLER(get_update_region)
 
     if (reply->flags & (UPDATE_PAINT|UPDATE_INTERNALPAINT)) /* validate everything */
     {
+        validate_parents( win );
         validate_whole_window( win );
     }
     else