Merged revisions 79792 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

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r79792 | russell | 2007-08-16 17:32:33 -0500 (Thu, 16 Aug 2007) | 4 lines

Fix a little race condition that could cause a crash if two channels had MOH
stopped at the same time that were using a class that had been marked for
deletion when its use count hits zero.

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@79794 65c4cc65-6c06-0410-ace0-fbb531ad65f3