[mutter/gnome-3-36] x11: Clear X11 selection source after unsetting owner

[Robert Mader <rmader src gnome org>]

commit a32bb758f7a744f17b829c02145c714dde692a9c
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Apr 17 14:13:50 2020 +0200

    x11: Clear X11 selection source after unsetting owner
    
    The X11 selection source was being preserved after unsetting its
    ownership. This is no leak as it would be eventually replaced by
    another source, or destroyed on finalize. But it's pointless to
    keep it.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1206
    
    (cherry picked from commit 94b3c334e5a141f68911c6e69fa2dab49ff260b7)

 src/x11/meta-x11-selection.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/x11/meta-x11-selection.c b/src/x11/meta-x11-selection.c
index 24a075b58..b2d524f35 100644
--- a/src/x11/meta-x11-selection.c
+++ b/src/x11/meta-x11-selection.c
@@ -339,6 +339,7 @@ meta_x11_selection_handle_xfixes_selection_notify (MetaX11Display *x11_display,
           /* An X client went away, clear the selection */
           meta_selection_unset_owner (selection, selection_type,
                                       x11_display->selection.owners[selection_type]);
+          g_clear_object (&x11_display->selection.owners[selection_type]);
         }
     }
   else if (event->owner != x11_display->selection.xwindow)