Merged revisions 260049 via svnmerge from

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

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  r260049 | dvossel | 2010-04-29 10:31:02 -0500 (Thu, 29 Apr 2010) | 14 lines
  
  Fixes crash in audiohook_write_list
  
  The middle_frame in the audiohook_write_list function was
  being freed if a audiohook manipulator returned a failure.
  This is incorrect logic.  This patch resolves this and
  adds detailed descriptions of how this function should work
  and why manipulator failures must be ignored.
  
  (closes issue #17052)
  Reported by: dvossel
  Tested by: dvossel

  (closes issue #16196)
  Reported by: atis
  
  Review: https://reviewboard.asterisk.org/r/623/
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@260050 65c4cc65-6c06-0410-ace0-fbb531ad65f3