Merged revisions 330312 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/10

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  r330312 | irroot | 2011-07-30 17:34:41 +0200 (Sat, 30 Jul 2011) | 15 lines
  
  Merged revisions 330311 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.8
  
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    r330311 | irroot | 2011-07-30 17:25:16 +0200 (Sat, 30 Jul 2011) | 9 lines
    
    prevent double masqurading channels when one is been hung up and deadlock avoidance is used.
    
    There is a race condition in ast_do_masquerade / ast_hangup (at least)
    
    Reported by me signed off by schmidts with input from David Vossel
    
    Review: https://reviewboard.asterisk.org/r/1323/
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@330313 65c4cc65-6c06-0410-ace0-fbb531ad65f3