$NetBSD: patch-aj,v 1.1 2007/10/10 17:12:53 rillig Exp $

--- lib/timezone.c.orig	2005-03-05 20:37:51.000000000 +0000
+++ lib/timezone.c	2007-10-10 17:08:30.000000000 +0000
@@ -18,6 +18,8 @@
 #define LETOH16(x)  x = letoh16(x)
 #define LETOH32(x)  x = letoh32(x)
 
+#define myisalnum(c)    isalnum((unsigned char)(c))
+
 static const uint8_t empty[6] = {0,0,0,0,0,0};
 
 /*
@@ -134,7 +136,7 @@ void rra_timezone_create_id(RRA_Timezone
 
   for (p = name; *p != '\0'; p++)
   {
-    if (!isalnum(*p))
+    if (!myisalnum(*p))
       *p = '_';
   }