libweston-desktop/xdg-shell: Check surface size against acknowledged size

We were checking against the pending size, which lead some clients
(simple-egl) to crash because they sent a buffer before acknowledging
the latest configure event.

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Tested-by: Emmanuel Gil Peyrot <emmanuel.peyrot@collabora.com>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>

libweston-desktop/xdg-shell-v5.c

@@ -60,6 +60,7 @@ struct weston_desktop_xdg_surface {
 	} pending;
 	struct {
 		struct weston_desktop_xdg_surface_state state;
+		struct weston_size size;
 	} next;
 	struct {
 		struct weston_desktop_xdg_surface_state state;
@@ -244,8 +245,8 @@ weston_desktop_xdg_surface_committed(struct weston_desktop_surface *dsurface,
 	bool reconfigure = false;
 
 	if (surface->next.state.maximized || surface->next.state.fullscreen)
-		reconfigure = surface->pending.size.width != wsurface->width ||
-			      surface->pending.size.height != wsurface->height;
+		reconfigure = surface->next.size.width != wsurface->width ||
+			      surface->next.size.height != wsurface->height;
 
 	if (reconfigure) {
 		weston_desktop_xdg_surface_schedule_configure(surface, true);
@@ -447,6 +448,7 @@ weston_desktop_xdg_surface_protocol_ack_configure(struct wl_client *wl_client,
 		return;
 
 	surface->next.state = surface->pending.state;
+	surface->next.size = surface->pending.size;
 }
 
 static void

libweston-desktop/xdg-shell-v6.c

@@ -95,6 +95,7 @@ struct weston_desktop_xdg_toplevel {
 	} pending;
 	struct {
 		struct weston_desktop_xdg_toplevel_state state;
+		struct weston_size size;
 		struct weston_size min_size, max_size;
 	} next;
 	struct {
@@ -424,6 +425,7 @@ static void
 weston_desktop_xdg_toplevel_ack_configure(struct weston_desktop_xdg_toplevel *toplevel)
 {
 	toplevel->next.state = toplevel->pending.state;
+	toplevel->next.size = toplevel->pending.size;
 }
 
 static void
@@ -626,8 +628,8 @@ weston_desktop_xdg_toplevel_committed(struct weston_desktop_xdg_toplevel *toplev
 		return;
 
 	if ((toplevel->next.state.maximized || toplevel->next.state.fullscreen) &&
-	    (toplevel->pending.size.width != wsurface->width ||
-	     toplevel->pending.size.height != wsurface->height)) {
+	    (toplevel->next.size.width != wsurface->width ||
+	     toplevel->next.size.height != wsurface->height)) {
 		struct weston_desktop_client *client =
 			weston_desktop_surface_get_client(toplevel->base.desktop_surface);
 		struct wl_resource *client_resource =