Backport fix from issue #9325.

(closes issue #11980)
Reported by: rbrunka


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@103768 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/asterisk.c

@@ -1721,7 +1721,8 @@ static int ast_el_read_char(EditLine *el, char *cp)
 	struct pollfd fds[2];
 	int res;
 	int max;
-	char buf[512];
+#define EL_BUF_SIZE 512
+	char buf[EL_BUF_SIZE];
 
 	for (;;) {
 		max = 1;
@@ -1784,7 +1785,7 @@ static int ast_el_read_char(EditLine *el, char *cp)
 			if (!ast_opt_exec && !lastpos)
 				write(STDOUT_FILENO, "\r", 1);
 			write(STDOUT_FILENO, buf, res);
-			if ((buf[res-1] == '\n') || (buf[res-2] == '\n')) {
+			if ((res < EL_BUF_SIZE - 1) && ((buf[res-1] == '\n') || (buf[res-2] == '\n'))) {
 				*cp = CC_REFRESH;
 				return(1);
 			} else {