[evolution-ews] Add only valid entries to prevent the crash.

[Bharath Acharya <abharath src gnome org>]

commit ab8bf5187f12d4b5813e7d87e1beee7ebb30ada8
Author: Bharath Acharya <abharath novell com>
Date:   Wed Jun 1 15:49:20 2011 +0530

    Add only valid entries to prevent the crash.

 src/server/e-ews-connection.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/server/e-ews-connection.c b/src/server/e-ews-connection.c
index 4e7c14c..61a4d56 100644
--- a/src/server/e-ews-connection.c
+++ b/src/server/e-ews-connection.c
@@ -574,7 +574,8 @@ resolve_names_response_cb (ESoapParameter *subparam, EwsNode *enode)
 
 		node = e_soap_parameter_get_first_child_by_name (subparam, "Mailbox");
 		mb = e_ews_item_mailbox_from_soap_param (node);
-		mailboxes = g_slist_append (mailboxes, mb);
+		if (mb)
+			mailboxes = g_slist_append (mailboxes, mb);
 
 		/* TODO parse contacts */
 	}