Fix two possible crashes, one only in 1.6.1 and one in 1.6.1 forward.

(closes issue #15739)
 Reported by: DLNoah, jeffg
 Patches: 
       20090914__issue15739.diff.txt uploaded by tilghman (license 14)
       20090922__issue15739.diff.txt uploaded by tilghman (license 14)
 Tested by: DLNoah, jeffg


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@219987 65c4cc65-6c06-0410-ace0-fbb531ad65f3