[gtk/mcatanzaro/company-unparent-warning] Add critical if widget has a parent during dispose

[Michael Catanzaro <mcatanzaro src gnome org>]

commit d7144f248dfaebeb4f1af5f5b2b100878ccfc2da
Author: Benjamin Otte <otte redhat com>
Date:   Thu Jan 7 09:49:52 2021 -0600

    Add critical if widget has a parent during dispose

 gtk/gtkwidget.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 239f7735e8..6efcdccc4a 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -7187,7 +7187,13 @@ gtk_widget_dispose (GObject *object)
     gtk_list_list_model_clear (priv->controller_observer);
 
   if (priv->parent)
-    gtk_widget_unparent (widget);
+    {
+      g_critical ("%s %p has a parent %s %p during dispose. Parents hold a reference, so this should not 
happen.\n"
+                  "Did you call g_object_unref() instead of gtk_widget_unparent()?",
+                  G_OBJECT_TYPE_NAME (widget), widget,
+                  G_OBJECT_TYPE_NAME (priv->parent), priv->parent);
+      priv->parent = NULL;
+    }
 
   while (priv->paintables)
     gtk_widget_paintable_set_widget (priv->paintables->data, NULL);