chan_sip: On INVITE retransmission, don't add an extra 503 response.

INVITE arrives to asterisk, asterisk responds Busy(). If the INVITE is
retransmitted, asterisk would generate a 503 in addition to the 486.

Thanks Torrey Searle for providing a working regression test.

ASTERISK-24335 #close

Review: https://reviewboard.asterisk.org/r/4003/
Patches:
  retrans_486_invite.patch uploaded by Torrey Searle (License #5334)
........

Merged revisions 423720 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 423721 from http://svn.asterisk.org/svn/asterisk/branches/11

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@423722 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 5f1af9960ee3efeb76a1b07ab8815519b3bda7f3..8c8efcb1a2a7ac41796c5ac6ff0a17037097bd76 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -26016,7 +26016,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, str
                        break;
                }
        } else {
-               if (p && (p->autokillid == -1)) {
+               if (!req->ignore && p && (p->autokillid == -1)) {
                        const char *msg;
 
                        if ((ast_format_cap_is_empty(p->jointcaps)))