Merged revisions 235052 via svnmerge from

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

........
  r235052 | tilghman | 2009-12-15 09:29:24 -0600 (Tue, 15 Dec 2009) | 4 lines
  
  Mandatory argument checking
  (closes issue #16446)
   Reported by: nicchap
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@235053 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_agi.c

@@ -2553,6 +2553,9 @@ static int handle_noop(struct ast_channel *chan, AGI *agi, int arg, const char *
 
 static int handle_setmusic(struct ast_channel *chan, AGI *agi, int argc, const char * const argv[])
 {
+	if (argc < 3) {
+		return RESULT_SHOWUSAGE;
+	}
 	if (!strncasecmp(argv[2], "on", 2))
 		ast_moh_start(chan, argc > 3 ? argv[3] : NULL, NULL);
 	else if (!strncasecmp(argv[2], "off", 3))