$NetBSD: patch-ad,v 1.1 2010/01/31 17:10:08 spz Exp $

--- filter.c.orig	2007-03-07 21:50:24.000000000 +0000
+++ filter.c
@@ -164,7 +164,8 @@ bool filter_apply_chain (struct filter *
 		if (dup2 (pipes[0], fileno (stdin)) == -1)
 			flexfatal (_("dup2(pipes[0],0)"));
 		close (pipes[0]);
-        fseek (stdin, 0, SEEK_CUR);
+        ungetc(' ', stdin); /* still an evil hack, but one that works better */
+	(void)fgetc(stdin); /* on NetBSD than the fseek attempt does */
 
 		/* run as a filter, either internally or by exec */
 		if (chain->filter_func) {