Handle case where an unknown format is used to get the preferred codec size
In ast_codec_pref_getsize, if an unknown format is passed to the method,
no preferred codec will be selected and a negative number will be used to
index into the format list. The method now logs an unknown format as a
warning, and returns an empty format list.
(issue ASTERISK-19655)
Reported by: Matt Jordan
Review: https://reviewboard.asterisk.org/r/1863/
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Merged revisions 362377 from http://svn.asterisk.org/svn/asterisk/branches/10
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@362380
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