When converting this code to use the list macros, I changed it so objects are

added to the head of a bucket instead of the tail.  However, while looking over
code with mmichelson, we noticed that the algorithm used in ao2_iterator_next
requires that items are added to the tail.  This wouldn't have caused any huge
problem, but it wasn't correct.  It meant that if an object was added to a
container while you were iterating it, and it was added to the same bucket that
the current element is in, then the new object would be returned by 
ao2_iterator_next, and any other objects in the bucket would be bypassed in
the traversal.


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@80424 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/astobj2.c

@@ -339,7 +339,7 @@ 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_HEAD(&c->buckets[i], p, entry);
+	AST_LIST_INSERT_TAIL(&c->buckets[i], p, entry);
 	ast_atomic_fetchadd_int(&c->elements, 1);
 	ao2_unlock(c);