From d90ef475926d4b90e42ef28c249ffbc4d2291768 Mon Sep 17 00:00:00 2001
From: Mark Michelson <mmichelson@digium.com>
Date: Wed, 11 Mar 2009 00:52:22 +0000
Subject: [PATCH] Merged revisions 181032-181033 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/trunk

................
  r181032 | mmichelson | 2009-03-10 19:46:47 -0500 (Tue, 10 Mar 2009) | 19 lines

  Merged revisions 181029,181031 via svnmerge from
  https://origsvn.digium.com/svn/asterisk/branches/1.4

  ........
    r181029 | mmichelson | 2009-03-10 19:30:26 -0500 (Tue, 10 Mar 2009) | 9 lines

    Fix incorrect tag checking on transfers when pedantic=yes is enabled.

    (closes issue #14611)
    Reported by: klaus3000
    Patches:
          patch_chan_sip_attended_transfer_1.4.23.txt uploaded by klaus3000 (license 65)
    Tested by: klaus3000
  ........
    r181031 | mmichelson | 2009-03-10 19:32:40 -0500 (Tue, 10 Mar 2009) | 3 lines

    Remove unused variables.
  ........
................
  r181033 | mmichelson | 2009-03-10 19:49:00 -0500 (Tue, 10 Mar 2009) | 3 lines

  Add missing comment that quotes RFC 3891
................


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.0@181034 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 channels/chan_sip.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 176a80193c..1bdb585065 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -11092,6 +11092,21 @@ static struct sip_pvt *get_sip_pvt_byid_locked(const char *callid, const char *t
 			   (With a forking SIP proxy, several call legs share the
 			   call id, but have different tags)
 			*/
+			
+			/* RFC 3891
+			 * > 3.  User Agent Server Behavior: Receiving a Replaces Header
+			 * > The Replaces header contains information used to match an existing
+			 * > SIP dialog (call-id, to-tag, and from-tag).  Upon receiving an INVITE
+			 * > with a Replaces header, the User Agent (UA) attempts to match this
+			 * > information with a confirmed or early dialog.  The User Agent Server
+			 * > (UAS) matches the to-tag and from-tag parameters as if they were tags
+			 * > present in an incoming request.  In other words, the to-tag parameter
+			 * > is compared to the local tag, and the from-tag parameter is compared
+			 * > to the remote tag.
+			 *
+			 * Thus, the totag is always compared to the local tag, regardless if
+			 * this our call is an incoming or outgoing call.
+			 */
 			if (pedanticsipchecking && (strcmp(fromtag, sip_pvt_ptr->theirtag) || (!ast_strlen_zero(totag) && strcmp(totag, ourtag))))
 				match = 0;