Merged revisions 150635 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

........
  r150635 | tilghman | 2008-10-17 12:09:03 -0500 (Fri, 17 Oct 2008) | 2 lines
  
  Make helper call a little safer (suggested by Russell on IRC)
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git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.1@150636 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -2312,8 +2312,9 @@ static void iax2_destroy(int callno)
 	struct ast_channel *owner = NULL;
 
 retry:
-	pvt = iaxs[callno];
-	iax2_destroy_helper(pvt);
+	if ((pvt = iaxs[callno])) {
+		iax2_destroy_helper(pvt);
+	}
 
 	lastused[callno] = ast_tvnow();