[gtk] widget: Properly remove event controllers in finalize

[Timm Bäder <baedert src gnome org>]

commit 3edd24fb0152789fc383568a14b38792a2c9b535
Author: Timm Bäder <mail baedert org>
Date:   Sat May 19 23:03:32 2018 +0200

    widget: Properly remove event controllers in finalize
    
    We were mutating the list while iterating over it. This was not a
    problem before since remove_controller just set the controller pointer
    to NULL instead of actually removing it from the list of controllers.

 gtk/gtkwidget.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 4727e37b4d..96c7145aa6 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -8572,15 +8572,18 @@ gtk_widget_finalize (GObject *object)
 
   _gtk_size_request_cache_free (&priv->requests);
 
-  for (l = priv->event_controllers; l; l = l->next)
+  l = priv->event_controllers;
+  while (l)
     {
+      GList *next = l->next;
       GtkEventController *controller = l->data;
 
       if (controller)
         gtk_widget_remove_controller (widget, controller);
+
+      l = next;
     }
-  g_list_free (priv->event_controllers);
-  priv->event_controllers = NULL;
+  g_assert (priv->event_controllers == NULL);
 
   if (_gtk_widget_get_first_child (widget) != NULL)
     {