Fix an incorrect assumption that certain values on the channel will always exist when they may not.

The CDR code involved with bridges wrongly assumed that the currently executing application and data
values will always exist. It is possible for this to be false when call forwarding is involved.

(closes issue #14984)
Reported by: gincantalupo


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@192454 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_features.c

@@ -1728,16 +1728,16 @@ int ast_bridge_call(struct ast_channel *chan,struct ast_channel *peer,struct ast
 			ast_set_flag(chan_cdr, AST_CDR_FLAG_MAIN);
 			ast_cdr_update(chan);
 			bridge_cdr = ast_cdr_dup(chan_cdr);
-			ast_copy_string(bridge_cdr->lastapp, chan->appl, sizeof(bridge_cdr->lastapp));
-			ast_copy_string(bridge_cdr->lastdata, chan->data, sizeof(bridge_cdr->lastdata));
+			ast_copy_string(bridge_cdr->lastapp, S_OR(chan->appl, ""), sizeof(bridge_cdr->lastapp));
+			ast_copy_string(bridge_cdr->lastdata, S_OR(chan->data, ""), sizeof(bridge_cdr->lastdata));
 		} else {
 			/* better yet, in a xfer situation, find out why the chan cdr got zapped (pun unintentional) */
 			bridge_cdr = ast_cdr_alloc(); /* this should be really, really rare/impossible? */
 			ast_copy_string(bridge_cdr->channel, chan->name, sizeof(bridge_cdr->channel));
 			ast_copy_string(bridge_cdr->dstchannel, peer->name, sizeof(bridge_cdr->dstchannel));
 			ast_copy_string(bridge_cdr->uniqueid, chan->uniqueid, sizeof(bridge_cdr->uniqueid));
-			ast_copy_string(bridge_cdr->lastapp, chan->appl, sizeof(bridge_cdr->lastapp));
-			ast_copy_string(bridge_cdr->lastdata, chan->data, sizeof(bridge_cdr->lastdata));
+			ast_copy_string(bridge_cdr->lastapp, S_OR(chan->appl, ""), sizeof(bridge_cdr->lastapp));
+			ast_copy_string(bridge_cdr->lastdata, S_OR(chan->data, ""), sizeof(bridge_cdr->lastdata));
 			ast_cdr_setcid(bridge_cdr, chan);
 			bridge_cdr->disposition = (chan->_state == AST_STATE_UP) ?  AST_CDR_ANSWERED : AST_CDR_NULL;
 			bridge_cdr->amaflags = chan->amaflags ? chan->amaflags :  ast_default_amaflags;