user32: Don't invalidate DCEs for sibling top-level windows since they are not clipped.

dlls/user32/painting.c

@@ -425,11 +425,11 @@ void invalidate_dce( HWND hwnd, const RECT *extra_rect )
         if (dce->hwnd == hwnd || IsChild( hwnd, dce->hwnd ))
         {
             make_dc_dirty( dce );
+            continue;
         }
-        else  /* otherwise check if the window rectangle intersects this DCE window */
-        {
-            if (hwndScope == GetDesktopWindow() ||
-                hwndScope == dce->hwnd || IsChild( hwndScope, dce->hwnd ))
+
+        /* otherwise check if the window rectangle intersects this DCE window */
+        if (hwndScope == dce->hwnd || IsChild( hwndScope, dce->hwnd ))
         {
             RECT dce_rect, tmp;
             GetWindowRect( dce->hwnd, &dce_rect );
@@ -438,7 +438,6 @@ void invalidate_dce( HWND hwnd, const RECT *extra_rect )
                 make_dc_dirty( dce );
         }
     }
-    }
     USER_Unlock();
 }