[gthumb] ignore null lists

[Paolo Bacchilega <paobac src gnome org>]

commit 5b8b267a5e80846a479b193a2e94c2d311c7e26a
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Jul 16 09:04:11 2010 +0200

    ignore null lists

 gthumb/gth-string-list.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gthumb/gth-string-list.c b/gthumb/gth-string-list.c
index e159403..5f541f1 100644
--- a/gthumb/gth-string-list.c
+++ b/gthumb/gth-string-list.c
@@ -190,6 +190,11 @@ gth_string_list_append (GthStringList *list1,
 {
 	GList *scan;
 
+	g_return_if_fail (GTH_IS_STRING_LIST (list1));
+
+	if (list2 == NULL)
+		return;
+
 	for (scan = list2->priv->list; scan; scan = scan->next)
 		if (! g_list_find_custom (list1->priv->list, scan->data, (GCompareFunc) strcmp))
 			list1->priv->list = g_list_append (list1->priv->list, g_strdup (scan->data));