[dconf] engine: allow NULL handle

[Ryan Lortie <desrt src gnome org>]

commit f75da1af04b2e96bd46bc16d1feb5e4ce991b571
Author: Ryan Lortie <desrt desrt ca>
Date:   Mon Nov 25 15:21:32 2013 -0500

    engine: allow NULL handle
    
    We use a NULL handle in case we don't care about the return value.  In that
    case, we certainly don't care about the return type either, so use NULL for
    expected_type in this case.

 engine/dconf-engine.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/engine/dconf-engine.c b/engine/dconf-engine.c
index 706a856..af98cdf 100644
--- a/engine/dconf-engine.c
+++ b/engine/dconf-engine.c
@@ -707,7 +707,10 @@ dconf_engine_call_handle_new (DConfEngine                   *engine,
 const GVariantType *
 dconf_engine_call_handle_get_expected_type (DConfEngineCallHandle *handle)
 {
-  return handle->expected_reply;
+  if (handle)
+    return handle->expected_reply;
+  else
+    return NULL;
 }
 
 void