[glib: 10/12] gobject: Weaken an assertion in g_weak_ref_set()

[Philip Withnall <pwithnall src gnome org>]

commit 94ba14d5424c9304342a601cb9eb0842e56d8f51
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Sun Jul 3 14:56:44 2022 -0400

    gobject: Weaken an assertion in g_weak_ref_set()
    
    When weak references are being cleaned up, it is possible for the `qdata` for
    both `quark_weak_locations` and `quark_weak_refs` to have been deallocated,
    so that `g_datalist_id_get_data()` returns `NULL` for both. This happens
    when `g_object_run_dispose()` is called for the target of a `GBinding`,
    and is not an error.
    
    See https://gitlab.gnome.org/GNOME/glib/-/issues/2676

 gobject/gobject.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)
---
diff --git a/gobject/gobject.c b/gobject/gobject.c
index df908984b7..2217e5c4b2 100644
--- a/gobject/gobject.c
+++ b/gobject/gobject.c
@@ -5059,16 +5059,22 @@ g_weak_ref_set (GWeakRef *weak_ref,
       /* Remove the weak ref from the old object */
       if (old_object != NULL)
         {
+          gboolean in_weak_refs_notify;
+
           weak_locations = g_datalist_id_get_data (&old_object->qdata, quark_weak_locations);
+          in_weak_refs_notify = g_datalist_id_get_data (&old_object->qdata, quark_weak_refs) == NULL;
           /* for it to point to an object, the object must have had it added once */
-          g_assert (weak_locations != NULL);
-
-          *weak_locations = g_slist_remove (*weak_locations, weak_ref);
+          g_assert (weak_locations != NULL || in_weak_refs_notify);
 
-          if (!*weak_locations)
+          if (weak_locations != NULL)
             {
-              weak_locations_free_unlocked (weak_locations);
-              g_datalist_id_remove_no_notify (&old_object->qdata, quark_weak_locations);
+              *weak_locations = g_slist_remove (*weak_locations, weak_ref);
+
+              if (!*weak_locations)
+                {
+                  weak_locations_free_unlocked (weak_locations);
+                  g_datalist_id_remove_no_notify (&old_object->qdata, quark_weak_locations);
+                }
             }
         }