[pygobject/pygobject-3-28] GValue override: chain up __del__

[Christoph Reiter <creiter src gnome org>]

commit b8bffa925566e561bb6270db5aecbe2b7b70d178
Author: Mathieu Duponchelle <mathieu centricular com>
Date:   Tue Mar 13 19:12:23 2018 +0100

    GValue override: chain up __del__
    
    This was added in d08e244d , which was recently reverted, that
    specific bit was however unrelated and still relevant.
    
    Fix #176

 gi/overrides/GObject.py | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gi/overrides/GObject.py b/gi/overrides/GObject.py
index bfcf7ccf..c252bfac 100644
--- a/gi/overrides/GObject.py
+++ b/gi/overrides/GObject.py
@@ -221,6 +221,9 @@ class Value(GObjectModule.Value):
         if self._free_on_dealloc and self.g_type != TYPE_INVALID:
             self.unset()
 
+        # We must call base class __del__() after unset.
+        super(Value, self).__del__()
+
     def set_boxed(self, boxed):
         # Workaround the introspection marshalers inability to know
         # these methods should be marshaling boxed types. This is because