# HG changeset patch
# Parent  047fa9d20b78759029e87c48f0d64f819e889e4c

diff --git a/widget/gtk/mozcontainer.cpp b/widget/gtk/mozcontainer.cpp
--- a/widget/gtk/mozcontainer.cpp
+++ b/widget/gtk/mozcontainer.cpp
@@ -159,23 +159,25 @@ void moz_container_move(MozContainer* co
 
   // Wayland subsurface is not created yet.
   if (!container->subsurface) {
     return;
   }
 
   // wl_subsurface_set_position is actually property of parent surface
   // which is effective when parent surface is commited.
-  wl_surface* parent_surface =
-      moz_gtk_widget_get_wl_surface(GTK_WIDGET(container));
-  if (parent_surface) {
-    wl_subsurface_set_position(container->subsurface, container->subsurface_dx,
-                               container->subsurface_dy);
-    wl_surface_commit(parent_surface);
-    container->surface_position_needs_update = false;
+  wl_subsurface_set_position(container->subsurface, container->subsurface_dx,
+                             container->subsurface_dy);
+  container->surface_position_needs_update = false;
+
+  GdkWindow* window = gtk_widget_get_window(GTK_WIDGET(container));
+  if (window) {
+    GdkRectangle rect = (GdkRectangle){0, 0, gdk_window_get_width(window),
+                                       gdk_window_get_height(window)};
+    gdk_window_invalidate_rect(window, &rect, false);
   }
 }
 
 // This is called from layout/compositor code only with
 // size equal to GL rendering context. Otherwise there are
 // rendering artifacts as wl_egl_window size does not match
 // GL rendering pipeline setup.
 void moz_container_egl_window_set_size(MozContainer* container, int width,
@@ -217,16 +219,17 @@ void moz_container_init(MozContainer* co
   container->subsurface = nullptr;
   container->eglwindow = nullptr;
   container->frame_callback_handler = nullptr;
   container->frame_callback_handler_surface_id = -1;
   // We can draw to x11 window any time.
   container->ready_to_draw = gfxPlatformGtk::GetPlatform()->IsX11Display();
   container->opaque_region_needs_update = false;
   container->opaque_region_subtract_corners = false;
+  container->opaque_region_fullscreen = false;
   container->surface_needs_clear = true;
   container->subsurface_dx = 0;
   container->subsurface_dy = 0;
   container->surface_position_needs_update = 0;
   container->initial_draw_cbs.clear();
 #endif
 
   LOG(("%s [%p]\n", __FUNCTION__, (void*)container));
@@ -569,22 +572,26 @@ static void moz_container_add(GtkContain
   moz_container_put(MOZ_CONTAINER(container), widget, 0, 0);
 }
 
 #ifdef MOZ_WAYLAND
 static void moz_container_set_opaque_region(MozContainer* container) {
   GtkAllocation allocation;
   gtk_widget_get_allocation(GTK_WIDGET(container), &allocation);
 
-  // Set region to mozcontainer which does not have any offset
-  wl_region* region =
-      CreateOpaqueRegionWayland(0, 0, allocation.width, allocation.height,
-                                container->opaque_region_subtract_corners);
-  wl_surface_set_opaque_region(container->surface, region);
-  wl_region_destroy(region);
+  // Set region to mozcontainer for normal state only
+  if (!container->opaque_region_fullscreen) {
+    wl_region* region =
+        CreateOpaqueRegionWayland(0, 0, allocation.width, allocation.height,
+                                  container->opaque_region_subtract_corners);
+    wl_surface_set_opaque_region(container->surface, region);
+    wl_region_destroy(region);
+  } else {
+    wl_surface_set_opaque_region(container->surface, nullptr);
+  }
 }
 
 struct wl_surface* moz_container_get_wl_surface(MozContainer* container) {
   LOGWAYLAND(("%s [%p] surface %p ready_to_draw %d\n", __FUNCTION__,
               (void*)container, (void*)container->surface,
               container->ready_to_draw));
 
   if (!container->surface) {
@@ -670,17 +677,19 @@ gboolean moz_container_has_wl_egl_window
 
 gboolean moz_container_surface_needs_clear(MozContainer* container) {
   int ret = container->surface_needs_clear;
   container->surface_needs_clear = false;
   return ret;
 }
 
 void moz_container_update_opaque_region(MozContainer* container,
-                                        bool aSubtractCorners) {
+                                        bool aSubtractCorners,
+                                        bool aFullScreen) {
   container->opaque_region_needs_update = true;
   container->opaque_region_subtract_corners = aSubtractCorners;
+  container->opaque_region_fullscreen = aFullScreen;
 }
 #endif
 
 void moz_container_force_default_visual(MozContainer* container) {
   container->force_default_visual = true;
 }
diff --git a/widget/gtk/mozcontainer.h b/widget/gtk/mozcontainer.h
--- a/widget/gtk/mozcontainer.h
+++ b/widget/gtk/mozcontainer.h
@@ -77,16 +77,17 @@ struct _MozContainer {
   struct wl_surface* surface;
   struct wl_subsurface* subsurface;
   int subsurface_dx, subsurface_dy;
   struct wl_egl_window* eglwindow;
   struct wl_callback* frame_callback_handler;
   int frame_callback_handler_surface_id;
   gboolean opaque_region_needs_update;
   gboolean opaque_region_subtract_corners;
+  gboolean opaque_region_fullscreen;
   gboolean surface_position_needs_update;
   gboolean surface_needs_clear;
   gboolean ready_to_draw;
   std::vector<std::function<void(void)>> initial_draw_cbs;
 #endif
   gboolean force_default_visual;
 };
 
@@ -112,12 +113,13 @@ void moz_container_move_resize(MozContai
 void moz_container_egl_window_set_size(MozContainer* container, int width,
                                        int height);
 void moz_container_scale_changed(MozContainer* container,
                                  GtkAllocation* aAllocation);
 void moz_container_add_initial_draw_callback(
     MozContainer* container, const std::function<void(void)>& initial_draw_cb);
 wl_surface* moz_gtk_widget_get_wl_surface(GtkWidget* aWidget);
 void moz_container_update_opaque_region(MozContainer* container,
-                                        bool aSubtractCorners);
+                                        bool aSubtractCorners,
+                                        bool aFullScreen);
 #endif
 
 #endif /* __MOZ_CONTAINER_H__ */
diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -4860,27 +4860,34 @@ void nsWindow::UpdateTopLevelOpaqueRegio
   int width = DevicePixelsToGdkCoordRoundDown(mBounds.width);
   int height = DevicePixelsToGdkCoordRoundDown(mBounds.height);
 
   GdkRectangle rect = {x, y, width, height};
   if (!mToplevelOpaqueRegionState.NeedsUpdate(rect, aSubtractCorners)) {
     return;
   }
 
-  wl_region* region =
-      CreateOpaqueRegionWayland(x, y, width, height, aSubtractCorners);
-  wl_surface_set_opaque_region(surface, region);
-  wl_region_destroy(region);
-
+  // Set opaque region to toplevel window only in fullscreen mode.
+  bool fullScreen = mSizeState != nsSizeMode_Normal && !mIsTiled;
+  if (fullScreen) {
+    wl_region* region =
+        CreateOpaqueRegionWayland(x, y, width, height, aSubtractCorners);
+    wl_surface_set_opaque_region(surface, region);
+    wl_region_destroy(region);
+  } else {
+    wl_surface_set_opaque_region(surface, nullptr);
+  }
+
+  // TODO -> create a function for it
   GdkWindow* window = gtk_widget_get_window(mShell);
   if (window) {
     gdk_window_invalidate_rect(window, &rect, false);
   }
 
-  moz_container_update_opaque_region(mContainer, aSubtractCorners);
+  moz_container_update_opaque_region(mContainer, aSubtractCorners, fullScreen);
 }
 #endif
 
 static void GdkWindowSetOpaqueRegion(GdkWindow* aGdkWindow,
                                      cairo_region_t* aRegion) {
   // Available as of GTK 3.10+
   static auto sGdkWindowSetOpaqueRegion =
       (void (*)(GdkWindow*, cairo_region_t*))dlsym(