Merged revisions 224855 via svnmerge from

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

........
  r224855 | tilghman | 2009-10-20 17:07:11 -0500 (Tue, 20 Oct 2009) | 5 lines
  
  Pay attention to the return value of the manipulate function.
  While this looks like an optimization, it prevents a crash from occurring
  when used with certain audiohook callbacks (diagnosed with SVN trunk,
  backported to 1.4 to keep the source consistent across versions).
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@224856 65c4cc65-6c06-0410-ace0-fbb531ad65f3