$NetBSD: patch-ay,v 1.3 2006/08/02 15:42:25 salo Exp $

Security fix for SA21304.

--- libtiff/tif_fax3.c.orig	2006-03-21 17:42:50.000000000 +0100
+++ libtiff/tif_fax3.c	2006-08-02 17:18:41.000000000 +0200
@@ -1136,6 +1136,7 @@ static int
 Fax3VSetField(TIFF* tif, ttag_t tag, va_list ap)
 {
 	Fax3BaseState* sp = Fax3State(tif);
+	const TIFFFieldInfo* fip;
 
 	assert(sp != 0);
 	assert(sp->vsetparent != 0);
@@ -1181,7 +1182,13 @@ Fax3VSetField(TIFF* tif, ttag_t tag, va_
 	default:
 		return (*sp->vsetparent)(tif, tag, ap);
 	}
-	TIFFSetFieldBit(tif, _TIFFFieldWithTag(tif, tag)->field_bit);
+	
+	if ((fip = _TIFFFieldWithTag(tif, tag))) {
+		TIFFSetFieldBit(tif, fip->field_bit);
+	} else {
+		return (0);
+	}
+
 	tif->tif_flags |= TIFF_DIRTYDIRECT;
 	return (1);
 }