gdk: Fix invalidation w/ pixel cache when changing child window geome…

…try.

When moving/scrolling a child window we can't use the current clip
region to limit what is invalidated, because there may be a pixel
cache that listens for changes outside the clip region. Instead
invalidate the entire area and rely on the invalidation code to limit
the repaint to the actually visible area.

gdk/gdkwindow.c

@@ -5761,11 +5761,16 @@ gdk_window_move_resize_internal (GdkWindow *window,
   if (gdk_window_is_viewable (window) &&
       !window->input_only)
     {
+      GdkRectangle r;
+
       expose = TRUE;
 
-      old_region = cairo_region_copy (window->clip_region);
-      /* Adjust regions to parent window coords */
-      cairo_region_translate (old_region, window->x, window->y);
+      r.x = window->x;
+      r.y = window->y;
+      r.width = window->width;
+      r.height = window->height;
+
+      old_region = cairo_region_create_rectangle (&r);
     }
 
   /* Set the new position and size */
@@ -5801,9 +5806,14 @@ gdk_window_move_resize_internal (GdkWindow *window,
 
   if (expose)
     {
-      new_region = cairo_region_copy (window->clip_region);
-      /* Adjust region to parent window coords */
-      cairo_region_translate (new_region, window->x, window->y);
+      GdkRectangle r;
+
+      r.x = window->x;
+      r.y = window->y;
+      r.width = window->width;
+      r.height = window->height;
+
+      new_region = cairo_region_create_rectangle (&r);
 
       cairo_region_union (new_region, old_region);
 
@@ -5940,7 +5950,7 @@ gdk_window_scroll (GdkWindow *window,
 
   move_native_children (window);
 
-  gdk_window_invalidate_region_full (window, window->clip_region, TRUE);
+  gdk_window_invalidate_rect_full (window, NULL, TRUE);
 
   _gdk_synthesize_crossing_events_for_geometry_change (window);
 }