[mutter/gnome-3-34] x11: Clear X11 selection source after unsetting owner

[Robert Mader <rmader src gnome org>]

commit 8acff5309de1ba061bae54debb47a87cc563e4c9
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 03d3c3b2d..1fb8aabe0 100644
--- a/src/x11/meta-x11-selection.c
+++ b/src/x11/meta-x11-selection.c
@@ -338,6 +338,7 @@ 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)