[gnumeric] GUI: Fix potential crash on exit.

[Morten Welinder <mortenw src gnome org>]

commit 438d0e5061082ded281f0e6fe3a8f9dc039314f4
Author: Morten Welinder <terra gnome org>
Date:   Mon Feb 21 12:00:05 2011 -0500

    GUI: Fix potential crash on exit.

 ChangeLog     |    2 ++
 src/wbc-gtk.c |    5 +++++
 2 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 42c02a3..c8471b7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,8 @@
 
 	* src/wbc-gtk.c (wbc_gtk_finalize): Cancel template loader handler
 	if necessary.
+	(wbc_gtk_create_notebook_area): Hold a ref to bnotebook so it
+	cannot disappear underneath us.
 
 2011-02-17  Morten Welinder  <terra gnome org>
 
diff --git a/src/wbc-gtk.c b/src/wbc-gtk.c
index 24586f2..881bd90 100644
--- a/src/wbc-gtk.c
+++ b/src/wbc-gtk.c
@@ -1090,6 +1090,8 @@ wbc_gtk_create_notebook_area (WBCGtk *wbcg)
 					"tab-hborder", 0,
 					"tab-vborder", 0,
 					NULL);
+	g_object_ref (wbcg->bnotebook);
+
 	g_signal_connect_after (G_OBJECT (wbcg->bnotebook),
 		"switch_page",
 		G_CALLBACK (cb_notebook_switch_page), wbcg);
@@ -5279,6 +5281,7 @@ wbc_gtk_finalize (GObject *obj)
 	}
 
 	g_hash_table_destroy (wbcg->custom_uis);
+	wbcg->custom_uis = NULL;
 
 	UNREF_OBJ (zoom_vaction);
 	UNREF_OBJ (zoom_haction);
@@ -5308,6 +5311,8 @@ wbc_gtk_finalize (GObject *obj)
 		g_signal_handlers_disconnect_by_func (
 			G_OBJECT (wbcg->bnotebook),
 			G_CALLBACK (cb_notebook_switch_page), wbcg);
+	UNREF_OBJ (bnotebook);
+
 	g_signal_handlers_disconnect_by_func (
 		G_OBJECT (wbcg->toplevel),
 		G_CALLBACK (cb_set_focus), wbcg);