wayland: Compare geometries after chaining upgbsneto/issue-150

After 20176d03, the Wayland backend only synchronizes with the
compositor after a geometry was set, and it was different from
the current geometry.

That commit was mistakenly comparing the geometry before chaining
up, which would yield a false negative on the case where the
client didn't call set_geometry() before commit().

Fix that by caching the old geometry locally, chain up (and thus
apply the new geometry rectangle), then comparing the old and
current geometry rectangles.

Fixes https://gitlab.gnome.org/GNOME/mutter/issues/150

2 files changed, 8 insertions, 29 deletions

diff --git a/src/wayland/meta-wayland-legacy-xdg-shell.c b/src/wayland/meta-wayland-legacy-xdg-shell.c
index cfc0dfedd..e871be972 100644
--- a/src/wayland/meta-wayland-legacy-xdg-shell.c
+++ b/src/wayland/meta-wayland-legacy-xdg-shell.c
@@ -585,17 +585,6 @@ is_new_size_hints_valid (MetaWindow              *window,
           (new_max_height == 0 || new_min_height <= new_max_height));
 }
 
-static inline gboolean
-did_geometry_change (MetaWaylandZxdgSurfaceV6 *xdg_surface,
-                     MetaWaylandPendingState  *pending)
-{
-  MetaWaylandZxdgSurfaceV6Private *priv =
-    meta_wayland_zxdg_surface_v6_get_instance_private (xdg_surface);
-
-  return pending->has_new_geometry &&
-         !meta_rectangle_equal (&priv->geometry, &pending->new_geometry);
-}
-
 static void
 meta_wayland_zxdg_toplevel_v6_commit (MetaWaylandSurfaceRole  *surface_role,
                                       MetaWaylandPendingState *pending)
@@ -611,11 +600,10 @@ meta_wayland_zxdg_toplevel_v6_commit (MetaWaylandSurfaceRole  *surface_role,
     meta_wayland_surface_role_get_surface (surface_role);
   MetaWindow *window = surface->window;
   MetaRectangle window_geometry;
+  MetaRectangle old_geometry;
   gboolean geometry_changed;
 
-  /* This check must happen before chaining up, otherwise the new geometry
-   * is applied and it'll always return FALSE. */
-  geometry_changed = did_geometry_change (xdg_surface, pending);
+  old_geometry = xdg_surface_priv->geometry;
 
   surface_role_class =
     META_WAYLAND_SURFACE_ROLE_CLASS (meta_wayland_zxdg_toplevel_v6_parent_class);
@@ -634,6 +622,8 @@ meta_wayland_zxdg_toplevel_v6_commit (MetaWaylandSurfaceRole  *surface_role,
   if (!window)
     return;
 
+  geometry_changed = !meta_rectangle_equal (&old_geometry, &xdg_surface_priv->geometry);
+
   if (geometry_changed || meta_window_wayland_needs_move_resize (window))
     {
       window_geometry =
diff --git a/src/wayland/meta-wayland-xdg-shell.c b/src/wayland/meta-wayland-xdg-shell.c
index a08520d31..41cdfc86b 100644
--- a/src/wayland/meta-wayland-xdg-shell.c
+++ b/src/wayland/meta-wayland-xdg-shell.c
@@ -608,17 +608,6 @@ is_new_size_hints_valid (MetaWindow              *window,
           (new_max_height == 0 || new_min_height <= new_max_height));
 }
 
-static inline gboolean
-did_geometry_change (MetaWaylandXdgSurface   *xdg_surface,
-                     MetaWaylandPendingState *pending)
-{
-  MetaWaylandXdgSurfacePrivate *priv =
-    meta_wayland_xdg_surface_get_instance_private (xdg_surface);
-
-  return pending->has_new_geometry &&
-         !meta_rectangle_equal (&priv->geometry, &pending->new_geometry);
-}
-
 static void
 meta_wayland_xdg_toplevel_commit (MetaWaylandSurfaceRole  *surface_role,
                                   MetaWaylandPendingState *pending)
@@ -632,6 +621,7 @@ meta_wayland_xdg_toplevel_commit (MetaWaylandSurfaceRole  *surface_role,
     meta_wayland_surface_role_get_surface (surface_role);
   MetaWindow *window;
   MetaRectangle window_geometry;
+  MetaRectangle old_geometry;
   gboolean geometry_changed;
 
   if (!surface->buffer_ref.buffer && xdg_surface_priv->first_buffer_attached)
@@ -641,10 +631,7 @@ meta_wayland_xdg_toplevel_commit (MetaWaylandSurfaceRole  *surface_role,
     }
 
   window = surface->window;
-
-  /* This check must happen before chaining up, otherwise the new geometry
-   * is applied and it'll always return FALSE. */
-  geometry_changed = did_geometry_change (xdg_surface, pending);
+  old_geometry = xdg_surface_priv->geometry;
 
   surface_role_class =
     META_WAYLAND_SURFACE_ROLE_CLASS (meta_wayland_xdg_toplevel_parent_class);
@@ -659,6 +646,8 @@ meta_wayland_xdg_toplevel_commit (MetaWaylandSurfaceRole  *surface_role,
   if (!pending->newly_attached)
     return;
 
+  geometry_changed = !meta_rectangle_equal (&old_geometry, &xdg_surface_priv->geometry);
+
   if (geometry_changed || meta_window_wayland_needs_move_resize (window))
     {
       window_geometry = meta_wayland_xdg_surface_get_window_geometry (xdg_surface);