closes issue #11233 -- where some fine points in the algorithm to build the...

closes issue #11233 -- where some fine points in the algorithm to build the tree needed to be corrected. Many thanks for the test case, jtodd

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89256 65c4cc65-6c06-0410-ace0-fbb531ad65f3