Merged revisions 196116 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r196116 | file | 2009-05-22 10:54:17 -0300 (Fri, 22 May 2009) | 5 lines
  
  Fix a bug where using immediate with mISDN caused a cause code of 16 to get sent back instead of 1 if the 's' extension did not exist.
  
  (closes issue #12286)
  Reported by: lmamane
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@196117 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_misdn.c

@@ -8171,8 +8171,9 @@ static void do_immediate_setup(struct misdn_bchannel *bc, struct chan_list *ch,
 
 	strcpy(ast->exten, "s");
 
-	if (pbx_start_chan(ch) < 0) {
+	if (!ast_canmatch_extension(ast, ast->context, ast->exten, 1, bc->oad) || pbx_start_chan(ch) < 0) {
 		ast = NULL;
+		bc->out_cause = AST_CAUSE_UNALLOCATED;
 		hangup_chan(ch);
 		hanguptone_indicate(ch);