stack: Don't recreate at contexts in dispose

This is the same protection we have in
GtkWidgetAccessible.

diff --git a/gtk/gtkstack.c b/gtk/gtkstack.c
index 0975ecf47268ba794a533b7b87942dda66bce0a1..59a3a0357ba0ac5df59b51d51f6261e82ecc4a22 100644 (file)
--- a/gtk/gtkstack.c
+++ b/gtk/gtkstack.c
@@ -219,6 +219,7 @@ struct _GtkStackPage
   guint needs_attention : 1;
   guint visible         : 1;
   guint use_underline   : 1;
+  guint in_destruction  : 1;
 };
 
 typedef struct _GtkStackPageClass GtkStackPageClass;
@@ -235,6 +236,14 @@ gtk_stack_page_accessible_get_at_context (GtkAccessible *accessible)
 {
   GtkStackPage *page = GTK_STACK_PAGE (accessible);
 
+  if (page->in_destruction)
+    {
+      GTK_DEBUG (A11Y, "ATContext for “%s” [%p] accessed during destruction",
+                       G_OBJECT_TYPE_NAME (accessible),
+                       accessible);
+      return NULL;
+    }
+
   if (page->at_context == NULL)
     {
       GtkAccessibleRole role = GTK_ACCESSIBLE_ROLE_TAB_PANEL;
@@ -353,6 +362,8 @@ gtk_stack_page_dispose (GObject *object)
 {
   GtkStackPage *page = GTK_STACK_PAGE (object);
 
+  page->in_destruction = TRUE;
+
   g_clear_object (&page->at_context);
 
   G_OBJECT_CLASS (gtk_stack_page_parent_class)->dispose (object);