[mutter/wip/carlosg/selection-fixes: 12/15] wayland: Check resource before emitting cancelled event

[Carlos Garnacho <carlosg src gnome org>]

commit 227d27204983f7be20536d79d216f76f80f5cceb
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Oct 11 17:47:00 2019 +0200

    wayland: Check resource before emitting cancelled event
    
    If a data source is destroyed we first unset the resource, and then try to
    unref the related selection source. At this point the only event that might
    be emitted by the internal selection machinery is .cancelled, so make sure
    we avoid it on destroyed sources.
    
    Fixes: https://gitlab.gnome.org/GNOME/mutter/issues/842

 src/wayland/meta-wayland-data-device.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/src/wayland/meta-wayland-data-device.c b/src/wayland/meta-wayland-data-device.c
index 24e97222a..3dfedd959 100644
--- a/src/wayland/meta-wayland-data-device.c
+++ b/src/wayland/meta-wayland-data-device.c
@@ -1369,7 +1369,8 @@ meta_wayland_source_cancel (MetaWaylandDataSource *source)
   MetaWaylandDataSourceWayland *source_wayland =
     META_WAYLAND_DATA_SOURCE_WAYLAND (source);
 
-  wl_data_source_send_cancelled (source_wayland->resource);
+  if (source_wayland->resource)
+    wl_data_source_send_cancelled (source_wayland->resource);
 }
 
 static void
@@ -1464,7 +1465,8 @@ meta_wayland_data_source_primary_cancel (MetaWaylandDataSource *source)
   MetaWaylandDataSourceWayland *source_wayland;
 
   source_wayland = META_WAYLAND_DATA_SOURCE_WAYLAND (source);
-  gtk_primary_selection_source_send_cancelled (source_wayland->resource);
+  if (source_wayland->resource)
+    gtk_primary_selection_source_send_cancelled (source_wayland->resource);
 }
 
 static void