From b2c65cf51df029712debd16ec380a6c49a7e0e72 Mon Sep 17 00:00:00 2001
From: Russell Bryant <russell@russellbryant.com>
Date: Thu, 23 Aug 2007 16:53:52 +0000
Subject: [PATCH] This is a hack to maintain old behavior of chan_iax2.  This
 ensures that if the peers and users are being stored in a linked list, that
 they go in the list in the same order that the older code used.  This is
 necessary to maintain the behavior of which peers and users get matched when
 traversing the container.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@80497 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 channels/chan_iax2.c       | 8 ++++----
 include/asterisk/astobj2.h | 9 ++++++++-
 main/astobj2.c             | 7 +++++--
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 958efbf0dc..546f14da10 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -9735,14 +9735,14 @@ static int set_config(char *config_file, int reload)
 					/* Start with general parameters, then specific parameters, user and peer */
 					user = build_user(cat, gen, ast_variable_browse(ucfg, cat), 0);
 					if (user) {
-						ao2_link(users, user);
+						__ao2_link(users, user, (MAX_PEER_BUCKETS == 1) ? 1 : 0);
 						user = NULL;
 					}
 					peer = build_peer(cat, gen, ast_variable_browse(ucfg, cat), 0);
 					if (peer) {
 						if (ast_test_flag(peer, IAX_DYNAMIC))
 							reg_source_db(peer);
-						ao2_link(peers, peer);
+						__ao2_link(peers, peer, (MAX_PEER_BUCKETS == 1) ? 1 : 0);
 						peer = NULL;
 					}
 				}
@@ -9779,7 +9779,7 @@ static int set_config(char *config_file, int reload)
 				if (!strcasecmp(utype, "user") || !strcasecmp(utype, "friend")) {
 					user = build_user(cat, ast_variable_browse(cfg, cat), NULL, 0);
 					if (user) {
-						ao2_link(users, user);
+						__ao2_link(users, user, (MAX_PEER_BUCKETS == 1) ? 1 : 0);
 						user = NULL;
 					}
 				}
@@ -9788,7 +9788,7 @@ static int set_config(char *config_file, int reload)
 					if (peer) {
 						if (ast_test_flag(peer, IAX_DYNAMIC))
 							reg_source_db(peer);
-						ao2_link(peers, peer);
+						__ao2_link(peers, peer, (MAX_PEER_BUCKETS == 1) ? 1 : 0);
 						peer = NULL;
 					}
 				} else if (strcasecmp(utype, "user")) {
diff --git a/include/asterisk/astobj2.h b/include/asterisk/astobj2.h
index 7663b1b652..cd0324dab1 100644
--- a/include/asterisk/astobj2.h
+++ b/include/asterisk/astobj2.h
@@ -368,8 +368,15 @@ int ao2_container_count(ao2_container *c);
  * This function insert an object in a container according its key.
  *
  * \note Remember to set the key before calling this function.
+ *
+ * For Asterisk 1.4 only, there is a dirty hack here to ensure that chan_iax2
+ * can have objects linked in to the container at the head instead of tail
+ * when it is just a linked list.  This is to maintain some existing behavior
+ * where the order must be maintained as it was before this conversion so that
+ * matching behavior doesn't change.
  */
-void *ao2_link(ao2_container *c, void *newobj);
+#define ao2_link(c, o) __ao2_link(c, o, 0)
+void *__ao2_link(ao2_container *c, void *newobj, int iax2_hack);
 void *ao2_unlink(ao2_container *c, void *newobj);
 
 /*! \struct Used as return value if the flag OBJ_MULTIPLE is set */
diff --git a/main/astobj2.c b/main/astobj2.c
index 4f338af44d..8c3e19446f 100644
--- a/main/astobj2.c
+++ b/main/astobj2.c
@@ -316,7 +316,7 @@ struct bucket_list {
 /*
  * link an object to a container
  */
-void *ao2_link(ao2_container *c, void *user_data)
+void *__ao2_link(ao2_container *c, void *user_data, int iax2_hack)
 {
 	int i;
 	/* create a new list entry */
@@ -339,7 +339,10 @@ void *ao2_link(ao2_container *c, void *user_data)
 	i %= c->n_buckets;
 	p->astobj = obj;
 	p->version = ast_atomic_fetchadd_int(&c->version, 1);
-	AST_LIST_INSERT_TAIL(&c->buckets[i], p, entry);
+	if (iax2_hack)
+		AST_LIST_INSERT_HEAD(&c->buckets[i], p, entry);
+	else
+		AST_LIST_INSERT_TAIL(&c->buckets[i], p, entry);
 	ast_atomic_fetchadd_int(&c->elements, 1);
 	ao2_unlock(c);