via-header branches not updated correctly on INVITE

INVITE requests must always contain a new unique branch id. When
a new branch id is created for an INVITE, the dialog's invite_branch
variable must be updated so CANCEL requests use the correct branch id.

(closes issue #15262)
Reported by: maniax
Patches:
      asterisk-1.6.1.0-sip-branch.patch uploaded by tweety (license 608)
      invite_new_branch_trunk.diff uploaded by dvossel (license 671)
Tested by: maniax, dvossel



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@219450 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -6316,13 +6316,14 @@ static int reqprep(struct sip_request *req, struct sip_pvt *p, int sipmethod, in
 		seqno = p->ocseq;
 	}
 	
-	/* A CANCEL must have the same branch as the INVITE that it is canceling.
-	 * Similarly, if we need to re-send an INVITE with auth credentials, then we
-	 * need to use the same branch as we did the first time we sent the INVITE.
-	 */
-	if (sipmethod == SIP_CANCEL || (sipmethod == SIP_INVITE && p->options && !ast_strlen_zero(p->options->auth))) {
+	/* A CANCEL must have the same branch as the INVITE that it is canceling. */
+	if (sipmethod == SIP_CANCEL) {
 		p->branch = p->invite_branch;
 		build_via(p);
+	} else if (newbranch && (sipmethod == SIP_INVITE)) {
+		p->branch ^= ast_random();
+		p->invite_branch = p->branch;
+		build_via(p);
 	} else if (newbranch) {
 		p->branch ^= ast_random();
 		build_via(p);