$NetBSD$

--- pppd/multilink.c.orig	2004-11-13 09:57:36.000000000 +0100
+++ pppd/multilink.c
@@ -570,7 +570,7 @@ str_to_epdisc(ep, str)
 		if (*str == 0)
 			break;
 		if (p <= str)
-			for (p = str; isxdigit(*p); ++p)
+			for (p = str; isxdigit((unsigned char)*p); ++p)
 				;
 		i = p - str;
 		if (i == 0)
