out of bounds access; detected by malloc guard; ok fgsch@

mail/fetchmail/patches/patch-rfc822_c

@@ -0,0 +1,21 @@
+$OpenBSD: patch-rfc822_c,v 1.1 2003/09/23 20:37:51 markus Exp $
+--- rfc822.c.orig	Thu Jul 17 03:03:20 2003
++++ rfc822.c	Tue Sep 23 11:23:05 2003
+@@ -176,7 +176,7 @@
+ 	    case 3:	/* we're in a <>-enclosed address */
+ 		if (*from == '@' || *from == '!')
+ 		    has_host_part = TRUE;
+-		else if (*from == '>' && from[-1] != '<')
++		else if (*from == '>' && (from > buf && from[-1] != '<'))
+ 		{
+ 		    state = 1;
+ 		    if (!has_host_part)
+@@ -198,7 +198,7 @@
+ 	/*
+ 	 * If we passed a comma, reset everything.
+ 	 */
+-	if (from[-1] == ',' && !parendepth) {
++	if ((from > buf && from[-1] == ',') && !parendepth) {
+ 	  has_host_part = has_bare_name_part = FALSE;
+ 	  parens_from = NULL;
+ 	}