[mutter] tests/stage-view: Test timelines notice stage views changing

[Jonas Ådahl <jadahl src gnome org>]

commit 090c72b3c32a393826e6d3bc52a647dc81ae70ab
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Aug 12 19:30:57 2020 +0200

    tests/stage-view: Test timelines notice stage views changing
    
    Timelines where the frame clock was picked from a parent of the
    associated actor didn't get notified about any stage views changes, as
    it only listened on the associated actor. If that actor didn't actually
    get its stage views changed (because it went from empty to empty), we'd
    end up with a stale frame clock, leading to crashes.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1404

 src/tests/stage-view-tests.c | 86 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
---
diff --git a/src/tests/stage-view-tests.c b/src/tests/stage-view-tests.c
index 684319d41f..cff212d4ff 100644
--- a/src/tests/stage-view-tests.c
+++ b/src/tests/stage-view-tests.c
@@ -814,6 +814,90 @@ meta_test_actor_stage_views_timeline (void)
   g_main_loop_unref (test.main_loop);
 }
 
+static void
+meta_test_actor_stage_views_parent_views_rebuilt (void)
+{
+  MetaBackend *backend = meta_get_backend ();
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  MetaMonitorManagerTest *monitor_manager_test =
+    META_MONITOR_MANAGER_TEST (monitor_manager);
+  MonitorTestCaseSetup frame_clock_test_setup;
+  MetaMonitorTestSetup *test_setup;
+  ClutterActor *stage, *container, *test_actor;
+  GList *stage_views;
+  ClutterTimeline *timeline;
+  ClutterFrameClock *timeline_frame_clock;
+  ClutterFrameClock *view_frame_clock;
+  ClutterStageView *old_stage_view;
+  ClutterFrameClock *old_frame_clock;
+
+  stage = meta_backend_get_stage (backend);
+
+  frame_clock_test_setup = initial_test_case_setup;
+  frame_clock_test_setup.n_outputs = 1;
+  frame_clock_test_setup.n_crtcs = 1;
+  test_setup = create_monitor_test_setup (&frame_clock_test_setup,
+                                          MONITOR_TEST_FLAG_NO_STORED);
+  meta_monitor_manager_test_emulate_hotplug (monitor_manager_test, test_setup);
+
+  stage_views = clutter_stage_peek_stage_views (CLUTTER_STAGE (stage));
+  g_assert_cmpint (g_list_length (stage_views), ==, 1);
+
+  container = clutter_actor_new ();
+  clutter_actor_set_size (container, 100, 100);
+  clutter_actor_set_position (container, 0, 0);
+  clutter_actor_add_child (stage, container);
+
+  test_actor = clutter_actor_new ();
+  clutter_actor_set_size (test_actor, 0, 0);
+  clutter_actor_add_child (container, test_actor);
+
+  clutter_actor_show (stage);
+  wait_for_paint (stage);
+
+  is_on_stage_views (test_actor, 0);
+  is_on_stage_views (container, 1, stage_views->data);
+  is_on_stage_views (stage, 1, stage_views->data);
+
+  timeline = clutter_timeline_new_for_actor (test_actor, 100);
+  clutter_timeline_start (timeline);
+
+  timeline_frame_clock = clutter_timeline_get_frame_clock (timeline);
+  view_frame_clock = clutter_stage_view_get_frame_clock (stage_views->data);
+  g_assert_nonnull (timeline_frame_clock);
+  g_assert_nonnull (view_frame_clock);
+  g_assert (timeline_frame_clock == view_frame_clock);
+
+  /* Keep the stage view alive so it can be used to compare with later. */
+  old_stage_view = g_object_ref (stage_views->data);
+  old_frame_clock =
+    g_object_ref (clutter_stage_view_get_frame_clock (old_stage_view));
+
+  test_setup = create_monitor_test_setup (&frame_clock_test_setup,
+                                          MONITOR_TEST_FLAG_NO_STORED);
+  meta_monitor_manager_test_emulate_hotplug (monitor_manager_test, test_setup);
+  wait_for_paint (stage);
+
+  stage_views = clutter_stage_peek_stage_views (CLUTTER_STAGE (stage));
+  g_assert_cmpint (g_list_length (stage_views), ==, 1);
+
+  g_assert (stage_views->data != old_stage_view);
+  view_frame_clock = clutter_stage_view_get_frame_clock (stage_views->data);
+  g_assert_nonnull (view_frame_clock);
+  g_assert (view_frame_clock != old_frame_clock);
+
+  timeline_frame_clock = clutter_timeline_get_frame_clock (timeline);
+  g_assert_nonnull (timeline_frame_clock);
+  g_assert (timeline_frame_clock == view_frame_clock);
+
+  g_object_unref (old_stage_view);
+  g_object_unref (old_frame_clock);
+
+  clutter_actor_destroy (test_actor);
+  clutter_actor_destroy (container);
+}
+
 static void
 init_tests (int argc, char **argv)
 {
@@ -835,6 +919,8 @@ init_tests (int argc, char **argv)
                    meta_test_actor_stage_views_frame_clock);
   g_test_add_func ("/stage-views/actor-stage-views-timeline",
                    meta_test_actor_stage_views_timeline);
+  g_test_add_func ("/stage-views/actor-stage-views-parent-rebuilt",
+                   meta_test_actor_stage_views_parent_views_rebuilt);
 }
 
 int