[dconf] don't return NULL on empty dconf_engine_list()

[Ryan Lortie <ryanl src gnome org>]

commit bc8fc387de46380ee5a57d8d877b4ec722eb742b
Author: Ryan Lortie <desrt desrt ca>
Date:   Thu May 27 22:23:52 2010 -0400

    don't return NULL on empty dconf_engine_list()
    
    the 'dconf' commandline tool assumes it is non-NULL and crashes.

 engine/dconf-engine.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/engine/dconf-engine.c b/engine/dconf-engine.c
index 382dc07..e708890 100644
--- a/engine/dconf-engine.c
+++ b/engine/dconf-engine.c
@@ -204,6 +204,9 @@ dconf_engine_list (DConfEngine    *engine,
 
   gvdb_table_unref (table);
 
+  if (list == NULL)
+    list = g_new0 (char *, 1);
+
   if (length)
     *length = g_strv_length (list);