Fix a crash when res_xmpp is configured using a username without a domain.

(closes issue ASTERISK-21156)
Reported by: amsoft2001
........

Merged revisions 382923 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@382924 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_xmpp.c

@@ -3772,8 +3772,8 @@ static int xmpp_client_config_post_apply(void *obj, void *arg, int flags)
 			cfg->client->jid = iks_id_new(cfg->client->stack, cfg->user);
 		}
 
-		if (!cfg->client->jid) {
-			ast_log(LOG_ERROR, "Jabber identity could not be created for client '%s' - client not active\n", cfg->name);
+		if (!cfg->client->jid || ast_strlen_zero(cfg->client->jid->user)) {
+			ast_log(LOG_ERROR, "Jabber identity '%s' could not be created for client '%s' - client not active\n", cfg->user, cfg->name);
 			return -1;
 		}