Merged revisions 335510 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/10

................
  r335510 | russell | 2011-09-13 02:24:34 -0500 (Tue, 13 Sep 2011) | 22 lines
  
  Merged revisions 335497 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.8
  
  ........
    r335497 | russell | 2011-09-13 02:11:36 -0500 (Tue, 13 Sep 2011) | 15 lines
    
    Fix a crash in res_ais.
    
    This patch resolves a crash observed in a load testing environment that
    involved the use of the res_ais module.  I observed some crashes where
    the event delivery callback would get called, but the length parameter
    incidcating how much data there was to read was 0.  The code assumed
    (with good reason I would think) that if this callback got called, there
    was an event available to read.  However, if the rare case that there's
    nothing there, catch it and return instead of blowing up.
    
    More specifically, the change always ensure that the size of the received
    event in the cluster is always big enough to be a real ast_event.
    
    Review: https://reviewboard.asterisk.org/r/1423/
  ........
................


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@335511 65c4cc65-6c06-0410-ace0-fbb531ad65f3