From da633dcc52768383497f5616bfb7eb7dddc12f73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 1 Jul 2020 00:14:46 +0200
Subject: [PATCH] clutter/actor: Allocate with the same box if deferred due to
 transition

When a transition is created for the allocation change, it will delay
the new allocation box getting set depending on transition details.
This, however, means that e.g. the 'needs_allocation' flag never gets
cleared if a transition is created, causing other parts of the code to
get confused thinking it didn't pass through a layout step before paint.

Fix this by calling clutter_actor_allocate_internal() with the current
allocation box if a transition was created, so that we'll properly clear
'needs_allocation' flag.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1345
---
 clutter/clutter/clutter-actor.c |  7 ++---
 src/tests/stage-view-tests.c    | 48 +++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index 7d3738ada..1a622c8d2 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -9599,9 +9599,10 @@ clutter_actor_allocate (ClutterActor          *self,
       goto out;
     }
 
-  _clutter_actor_create_transition (self, obj_props[PROP_ALLOCATION],
-                                    &priv->allocation,
-                                    &real_allocation);
+  if (_clutter_actor_create_transition (self, obj_props[PROP_ALLOCATION],
+                                        &priv->allocation,
+                                        &real_allocation))
+    clutter_actor_allocate_internal (self, &priv->allocation);
 
 out:
   priv->absolute_origin_changed = FALSE;
diff --git a/src/tests/stage-view-tests.c b/src/tests/stage-view-tests.c
index 9c31353e0..76da1db45 100644
--- a/src/tests/stage-view-tests.c
+++ b/src/tests/stage-view-tests.c
@@ -250,6 +250,52 @@ meta_test_actor_stage_views (void)
   clutter_actor_destroy (container);
 }
 
+static void
+on_relayout_actor_frame (ClutterTimeline *timeline,
+                         int              msec,
+                         ClutterActor    *actor)
+{
+  MetaBackend *backend = meta_get_backend ();
+  ClutterActor *stage = meta_backend_get_stage (backend);
+
+  clutter_stage_clear_stage_views (CLUTTER_STAGE (stage));
+}
+
+static void
+meta_test_actor_stage_views_relayout (void)
+{
+  MetaBackend *backend = meta_get_backend ();
+  ClutterActor *stage, *actor;
+  ClutterTransition *transition;
+  GMainLoop *main_loop;
+
+  stage = meta_backend_get_stage (backend);
+
+  actor = clutter_actor_new ();
+  clutter_actor_set_size (actor, 100, 100);
+  clutter_actor_set_easing_duration (actor, 100);
+  clutter_actor_add_child (stage, actor);
+
+  clutter_actor_show (stage);
+
+  wait_for_paint (stage);
+  clutter_actor_set_position (actor, 1000.0, 0.0);
+  transition = clutter_actor_get_transition (actor, "position");
+  g_signal_connect_after (transition, "new-frame",
+                          G_CALLBACK (on_relayout_actor_frame),
+                          actor);
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect_swapped (transition, "stopped",
+                            G_CALLBACK (g_main_loop_quit),
+                            main_loop);
+
+  g_main_loop_run (main_loop);
+
+  clutter_actor_destroy (actor);
+  g_main_loop_unref (main_loop);
+}
+
 static void
 meta_test_actor_stage_views_reparent (void)
 {
@@ -478,6 +524,8 @@ init_tests (int argc, char **argv)
                    meta_test_stage_views_exist);
   g_test_add_func ("/stage-views/actor-stage-views",
                    meta_test_actor_stage_views);
+  g_test_add_func ("/stage-views/actor-stage-views-relayout",
+                   meta_test_actor_stage_views_relayout);
   g_test_add_func ("/stage-views/actor-stage-views-reparent",
                    meta_test_actor_stage_views_reparent);
   g_test_add_func ("/stage-views/actor-stage-views-hide-parent",