[tracker] TrackerResultsWindow: Don't propagate signal up if parent class doesn't implement it.

[Carlos Garnacho <carlosg src gnome org>]

commit ee91d139b0e1bddf5412f28e38d7eafc3e8cf6cf
Author: Carlos Garnacho <carlos lanedo com>
Date:   Wed Sep 30 13:30:01 2009 +0200

    TrackerResultsWindow: Don't propagate signal up if parent class doesn't implement it.
    
    GtkWindow doesn't have any implementation for button_press_event, so going though the
    parent class implementation crashed.

 src/tracker-search-bar/tracker-results-window.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/tracker-search-bar/tracker-results-window.c b/src/tracker-search-bar/tracker-results-window.c
index b97ef07..3dc7e3c 100644
--- a/src/tracker-search-bar/tracker-results-window.c
+++ b/src/tracker-search-bar/tracker-results-window.c
@@ -380,7 +380,8 @@ results_window_button_press_event (GtkWidget      *widget,
 		return TRUE;
 	}
 
-	if (GTK_WIDGET_CLASS (tracker_results_window_parent_class)->button_press_event (widget, event)) {
+	if (GTK_WIDGET_CLASS (tracker_results_window_parent_class)->button_press_event &&
+	    GTK_WIDGET_CLASS (tracker_results_window_parent_class)->button_press_event (widget, event)) {
 		return TRUE;
 	}