Backport MR #2299 to avoid a commonly-encountered crash (#2063381)

2299.patch

@@ -0,0 +1,76 @@
+From 53de072634527c5f433911553d8f921a6e119ac1 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Jonas=20Dre=C3=9Fler?= <verdre@v0yd.nl>
+Date: Wed, 16 Feb 2022 22:34:12 +0100
+Subject: [PATCH] clutter: Bail out and warn on reentry into mapping/unmapping
+ cycle
+
+There's a bunch of crashes right now where the assertions in
+clutter_actor_set_mapped() after calling the map/unmap() vfuncs are
+failing. The only way this can happen is by re-entering
+clutter_actor_set_mapped() during the map/unmap recursion.
+
+The reason for those crashes is that the shell hides/shows some actors
+in response to crossing events and key-focus changes. These in turn get
+triggered by the newly introduced ungrabbing of ClutterGrabs when an
+actor gets unmapped, which triggers GRAB_NOTIFY crossing events and
+key-focus changes.
+
+Since these situations are hardly avoidable (it's a valid use-case to
+hide/show something in response to a crossing/key-focus event), catch
+the set_mapped() call early while we reenter the mapping machinery and
+log a warning instead of crashing.
+
+Fixes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3165
+---
+ clutter/clutter/clutter-actor.c   | 6 ++++++
+ clutter/clutter/clutter-private.h | 3 +++
+ 2 files changed, 9 insertions(+)
+
+diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
+index 59345a7252..bae11088dd 100644
+--- a/clutter/clutter/clutter-actor.c
++++ b/clutter/clutter/clutter-actor.c
+@@ -1264,6 +1264,10 @@ clutter_actor_set_mapped (ClutterActor *self,
+   if (CLUTTER_ACTOR_IS_MAPPED (self) == mapped)
+     return;
+ 
++  g_return_if_fail (!CLUTTER_ACTOR_IN_MAP_UNMAP (self));
++
++  CLUTTER_SET_PRIVATE_FLAGS (self, CLUTTER_IN_MAP_UNMAP);
++
+   if (mapped)
+     {
+       CLUTTER_ACTOR_GET_CLASS (self)->map (self);
+@@ -1274,6 +1278,8 @@ clutter_actor_set_mapped (ClutterActor *self,
+       CLUTTER_ACTOR_GET_CLASS (self)->unmap (self);
+       g_assert (!CLUTTER_ACTOR_IS_MAPPED (self));
+     }
++
++  CLUTTER_UNSET_PRIVATE_FLAGS (self, CLUTTER_IN_MAP_UNMAP);
+ }
+ 
+ /* this function updates the mapped and realized states according to
+diff --git a/clutter/clutter/clutter-private.h b/clutter/clutter/clutter-private.h
+index 377b318798..117902a35f 100644
+--- a/clutter/clutter/clutter-private.h
++++ b/clutter/clutter/clutter-private.h
+@@ -69,6 +69,7 @@ typedef struct _ClutterMainContext      ClutterMainContext;
+ #define CLUTTER_ACTOR_IN_PREF_WIDTH(a)          ((CLUTTER_PRIVATE_FLAGS (a) & CLUTTER_IN_PREF_WIDTH) != FALSE)
+ #define CLUTTER_ACTOR_IN_PREF_HEIGHT(a)         ((CLUTTER_PRIVATE_FLAGS (a) & CLUTTER_IN_PREF_HEIGHT) != FALSE)
+ #define CLUTTER_ACTOR_IN_PREF_SIZE(a)           ((CLUTTER_PRIVATE_FLAGS (a) & (CLUTTER_IN_PREF_HEIGHT|CLUTTER_IN_PREF_WIDTH)) != FALSE)
++#define CLUTTER_ACTOR_IN_MAP_UNMAP(a)           ((CLUTTER_PRIVATE_FLAGS (a) & CLUTTER_IN_MAP_UNMAP) != FALSE)
+ 
+ #define CLUTTER_PARAM_READABLE  (G_PARAM_READABLE | G_PARAM_STATIC_STRINGS)
+ #define CLUTTER_PARAM_WRITABLE  (G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS)
+@@ -105,6 +106,8 @@ typedef enum
+ 
+   /* Used to avoid recursion */
+   CLUTTER_IN_RELAYOUT    = 1 << 7,
++
++  CLUTTER_IN_MAP_UNMAP   = 1 << 8,
+ } ClutterPrivateFlags;
+ 
+ /*
+-- 
+GitLab
+

mutter.spec

@@ -10,7 +10,7 @@
 
 Name:          mutter
 Version:       42.0
-Release:       1%{?dist}
+Release:       2%{?dist}
 Summary:       Window and compositing manager based on Clutter
 
 License:       GPLv2+
@@ -32,6 +32,12 @@ Patch2:        mutter-42.alpha-disable-tegra.patch
 # https://bugzilla.redhat.com/show_bug.cgi?id=2017043
 Patch3:        2331.patch
 
+# Avoid crashing on reentry into mapping/unmapping cycle
+# https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3165
+# https://bugzilla.redhat.com/show_bug.cgi?id=2063381
+# https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2299
+Patch4:        2299.patch
+
 BuildRequires: pkgconfig(gobject-introspection-1.0) >= 1.41.0
 BuildRequires: pkgconfig(sm)
 BuildRequires: pkgconfig(libwacom)
@@ -175,6 +181,9 @@ desktop-file-validate %{buildroot}/%{_datadir}/applications/%{name}.desktop
 %{_datadir}/mutter-%{mutter_api_version}/tests
 
 %changelog
+* Mon Mar 14 2022 Adam Williamson <awilliam@redhat.com> - 42.0-2
+- Backport MR #2299 to avoid a commonly-encountered crash (#2063381)
+
 * Sun Mar 13 2022 Florian Müllner <fmuellner@redhat.com> - 42.0-1
 - Update to 42.0