[evolution-data-server] Fix crash in e_cal_client_get_objects_for_uid_sync().

[Matthew Barnes <mbarnes src gnome org>]

commit 4e93d32b5495559c212454067ce77901567412b5
Author: Matthew Barnes <mbarnes redhat com>
Date:   Wed Jan 30 13:06:30 2013 -0500

    Fix crash in e_cal_client_get_objects_for_uid_sync().

 calendar/libecal/e-cal-client.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/calendar/libecal/e-cal-client.c b/calendar/libecal/e-cal-client.c
index 79c49f5..2fb2a78 100644
--- a/calendar/libecal/e-cal-client.c
+++ b/calendar/libecal/e-cal-client.c
@@ -3757,6 +3757,9 @@ e_cal_client_get_objects_for_uid_sync (ECalClient *client,
 		(success && (string != NULL)) ||
 		(!success && (string == NULL)), FALSE);
 
+	if (!success)
+		return FALSE;
+
 	icalcomp = icalparser_parse_string (string);
 
 	g_free (string);