prevent periodic auto-save from causing GUI deadlock waiting for the Locations lock to be released while export-ranges happens. this fix might be updated with a better one later.

git-svn-id: svn://localhost/ardour2/branches/2.0-ongoing@3479 d708f5d6-7413-0410-9779-e7cbd77b26cf

gtk2_ardour/ardour_ui.cc

@@ -532,6 +532,14 @@ ARDOUR_UI::save_ardour_state ()
 gint
 ARDOUR_UI::autosave_session ()
 {
+	if (g_main_depth() > 1) {
+		/* inside a recursive main loop,
+		   give up because we may not be able to 
+		   take a lock.
+		*/
+		return 1;
+	}
+
         if (!Config->get_periodic_safety_backups())
                 return 1;