[mutter/gnome-41] x11/input-selection-stream: Handle Xwayland going away

[Jonas Ådahl <jadahl src gnome org>]

commit 16b7dce9cb1313d08a594c20697cea9d0b8812f0
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Apr 6 10:05:35 2022 +0200

    x11/input-selection-stream: Handle Xwayland going away
    
    Xwayland can disappear at any time, for example during a new_async() or
    read_async() call. When we eventually finalize the stream, the X11
    display it was created for is gone, thus can't clean up the X11
    resources. Handle this by making the MetaX11Display pointer a weak
    pointer, and ignore cleaning up if it disappeared. This is fine since
    the X11 server it created those resources one is gone already.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2364>

 src/x11/meta-x11-selection-input-stream.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)
---
diff --git a/src/x11/meta-x11-selection-input-stream.c b/src/x11/meta-x11-selection-input-stream.c
index e8d7820478..7ed64ac0b5 100644
--- a/src/x11/meta-x11-selection-input-stream.c
+++ b/src/x11/meta-x11-selection-input-stream.c
@@ -268,9 +268,14 @@ meta_x11_selection_input_stream_dispose (GObject *object)
     META_X11_SELECTION_INPUT_STREAM (object);
   MetaX11SelectionInputStreamPrivate *priv =
     meta_x11_selection_input_stream_get_instance_private (stream);
+  MetaX11Display *x11_display;
 
-  priv->x11_display->selection.input_streams =
-    g_list_remove (priv->x11_display->selection.input_streams, stream);
+  x11_display = priv->x11_display;
+  if (x11_display)
+    {
+      x11_display->selection.input_streams =
+        g_list_remove (x11_display->selection.input_streams, stream);
+    }
 
   G_OBJECT_CLASS (meta_x11_selection_input_stream_parent_class)->dispose (object);
 }
@@ -282,6 +287,7 @@ meta_x11_selection_input_stream_finalize (GObject *object)
     META_X11_SELECTION_INPUT_STREAM (object);
   MetaX11SelectionInputStreamPrivate *priv =
     meta_x11_selection_input_stream_get_instance_private (stream);
+  MetaX11Display *x11_display;
 
   g_async_queue_unref (priv->chunks);
 
@@ -289,6 +295,17 @@ meta_x11_selection_input_stream_finalize (GObject *object)
   g_free (priv->target);
   g_free (priv->property);
 
+  x11_display = priv->x11_display;
+  if (x11_display)
+    {
+      Display *xdisplay = meta_x11_display_get_xdisplay (x11_display);
+
+      XDestroyWindow (xdisplay, priv->window);
+
+      g_object_remove_weak_pointer (G_OBJECT (x11_display),
+                                    (gpointer *) &priv->x11_display);
+    }
+
   G_OBJECT_CLASS (meta_x11_selection_input_stream_parent_class)->finalize (object);
 }
 
@@ -520,6 +537,9 @@ meta_x11_selection_input_stream_new_async (MetaX11Display      *x11_display,
   priv = meta_x11_selection_input_stream_get_instance_private (stream);
 
   priv->x11_display = x11_display;
+  g_object_add_weak_pointer (G_OBJECT (x11_display),
+                             (gpointer *) &priv->x11_display);
+
   x11_display->selection.input_streams =
     g_list_prepend (x11_display->selection.input_streams, stream);
   priv->selection = g_strdup (selection);