$NetBSD: patch-ao,v 1.2 2011/05/17 10:36:45 hans Exp $

Fix build with "png" 1.5.1beta01 and newer.

--- wrlib/png.c.orig	2004-10-12 19:22:04.000000000 +0100
+++ wrlib/png.c	2011-01-14 19:38:22.000000000 +0000
@@ -97,7 +97,7 @@
     }
 
     RErrorCode = RERR_INTERNAL;
-    if (setjmp(png->jmpbuf)) {
+    if (setjmp(png_jmpbuf(png))) {
         fclose(f);
         png_destroy_read_struct(&png, &pinfo, &einfo);
         if (image)
