Merged revisions 296082 via svnmerge from

Merged revisions 296082 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

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  r296082 | russell | 2010-11-24 14:22:32 -0600 (Wed, 24 Nov 2010) | 12 lines

  Fix false reporting of an error by set_format().

  In the case that the native format was able to be changed to match the
  new requested format, the code proceeded to attempt to build a translation
  path, anyway.  The result would be NULL, since no translation path is
  necessary and resulted in this function thinking an error has occurred.
  This case is now specifically caught and no attempt to build a translation
  path is attempted.

  Thanks to our automated tests and bamboo.asterisk.org for catching this problem
  and making a whole lot of noise when things started failing.  :-)
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git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@296083 65c4cc65-6c06-0410-ace0-fbb531ad65f3