[gnome-builder] GbDocumentStack: work around some focus issues in GtkStack

[Christian Hergert <chergert src gnome org>]

commit 6b8dcea1a69ef977253a5071d14f9c4a4dd6f1a2
Author: Christian Hergert <christian hergert me>
Date:   Sat Dec 13 17:18:38 2014 -0800

    GbDocumentStack: work around some focus issues in GtkStack

 src/documents/gb-document-stack.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/src/documents/gb-document-stack.c b/src/documents/gb-document-stack.c
index 4b107bd..4606aa8 100644
--- a/src/documents/gb-document-stack.c
+++ b/src/documents/gb-document-stack.c
@@ -73,6 +73,7 @@ gb_document_stack_remove_view (GbDocumentStack *stack,
                                GbDocumentView  *view)
 {
   GbDocument *document = NULL;
+  GtkWidget *toplevel;
   GtkWidget *visible_child;
   GtkWidget *controls;
   gboolean visible;
@@ -86,6 +87,18 @@ gb_document_stack_remove_view (GbDocumentStack *stack,
 
   g_object_ref (view);
 
+  /*
+   * WORKAROUND:
+   *
+   * Clear the focus before we start removing stuff. Otherwise GtkStack
+   * can get pretty unhappy and segfault. Needs more investigation, but
+   * seems to help a bit. We refocus the new visible child afterwards
+   * anyway, so not too big of a deal.
+   */
+  toplevel = gtk_widget_get_toplevel (GTK_WIDGET (stack));
+  if (GTK_IS_WINDOW (toplevel))
+    gtk_window_set_focus (GTK_WINDOW (toplevel), NULL);
+
   /* Notify the document view it is being closed */
   gb_document_view_close (view);