[perl-Glib] Plug a leak in Glib::Object->signal_query

[Torsten SchÃnfeld <tsch src gnome org>]

commit a28f68cbefdc399e23ee3ebce8585653606b3758
Author: Torsten SchÃnfeld <kaffeetisch gmx de>
Date:   Mon Aug 8 17:23:06 2011 +0200

    Plug a leak in Glib::Object->signal_query
    
    Spotted by Kevin Ryde.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=653681

 GSignal.xs |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/GSignal.xs b/GSignal.xs
index 5bdfffd..48c899e 100644
--- a/GSignal.xs
+++ b/GSignal.xs
@@ -657,10 +657,12 @@ g_signal_query (SV * object_or_class_name, const char * name)
 			croak ("couldn't ref type %s", g_type_name (itype));
 	}
 	signal_id = g_signal_lookup (name, itype);
-	if (0 == signal_id)
-		XSRETURN_UNDEF;
-	g_signal_query (signal_id, &query);
-	RETVAL = newSVGSignalQuery (&query);
+	if (0 == signal_id) {
+		RETVAL = &PL_sv_undef;
+	} else {
+		g_signal_query (signal_id, &query);
+		RETVAL = newSVGSignalQuery (&query);
+	}
 	if (oclass)
 		g_type_class_unref (oclass);
     OUTPUT: