Merged revisions 228827 via svnmerge from

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

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  r228827 | mnicholson | 2009-11-09 08:16:03 -0600 (Mon, 09 Nov 2009) | 8 lines
  
  Perform limited bounds checking when destroying ast_mutex_t structures to make sure we don't try to use negative indices.
  
  (closes issue #15588)
  Reported by: zerohalo
  Patches:
        20090820__issue15588.diff.txt uploaded by tilghman (license 14)
  Tested by: zerohalo
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@228858 65c4cc65-6c06-0410-ace0-fbb531ad65f3