[evolution-ews] Handle a condition where a NULL was passed to prepare_accept_item_request

[Shiran Stan-Meleh <sstanmel src gnome org>]

commit d2c3256f11d0d751894c76d2bd15da61eddc2b17
Author: Shiran Stan-Meleh <shiran stan-meleh intel com>
Date:   Wed Aug 24 11:50:44 2011 +0300

    Handle a condition where a NULL was passed to prepare_accept_item_request

 src/calendar/e-cal-backend-ews.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/calendar/e-cal-backend-ews.c b/src/calendar/e-cal-backend-ews.c
index a1a4367..2a12b67 100644
--- a/src/calendar/e-cal-backend-ews.c
+++ b/src/calendar/e-cal-backend-ews.c
@@ -2222,9 +2222,9 @@ prepare_accept_item_request (ESoapMessage *msg, gpointer user_data)
 	 * need to find current user as attendee and make a desision what to do.
 	 * Prepare AcceptItem node in the SOAP message */
 	
-	if (!g_ascii_strcasecmp (response_type, "ACCEPTED"))
+	if (response_type && !g_ascii_strcasecmp (response_type, "ACCEPTED"))
 		e_soap_message_start_element (msg, "AcceptItem", NULL, NULL);
-	else if (!g_ascii_strcasecmp (response_type, "DECLINED"))
+	else if (response_type && !g_ascii_strcasecmp (response_type, "DECLINED"))
 		e_soap_message_start_element (msg, "DeclineItem", NULL, NULL);
 	else
 		e_soap_message_start_element (msg, "TentativelyAcceptItem", NULL, NULL);