$NetBSD: patch-be,v 1.1 2005/12/29 23:31:36 joerg Exp $

--- src/gate/rfc2ftn.c.orig	2005-12-30 00:26:00.000000000 +0100
+++ src/gate/rfc2ftn.c
@@ -619,7 +619,7 @@ void cvt_user_name(char *s)
      * capitalized.  If no '_' chars are found, '.' are converted to
      * spaces (User.Name@p.f.n.z.fidonet.org addressing style).
      */
-    convert_flag = isupper(*s) ? -1 : 1;
+    convert_flag = isupper((unsigned char)*s) ? -1 : 1;
     us_flag      = strchr(s, '_') || strchr(s, ' ') || strchr(s, '@');
     
     for(; *s; s++) {
