[glib/new-gsettings] Do not crash when binding with no schema

[Vincent Untz <vuntz src gnome org>]

commit 41d50f655d7a8790d09da3b4c29719246f3706db
Author: Vincent Untz <vuntz gnome org>
Date:   Fri Apr 16 19:23:14 2010 -0400

    Do not crash when binding with no schema
    
    There's already a g_critical() call for this later on.

 gio/gsettings.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gio/gsettings.c b/gio/gsettings.c
index 28476ae..e79841f 100644
--- a/gio/gsettings.c
+++ b/gio/gsettings.c
@@ -1613,7 +1613,8 @@ g_settings_bind_with_mapping (GSettings               *settings,
 
     value = g_settings_schema_get_value (settings->priv->schema, key, NULL);
     binding->type = g_variant_type_copy (g_variant_get_type (value));
-    g_variant_unref (value);
+    if (value)
+      g_variant_unref (value);
   }
 
   if (binding->type == NULL)