From 05c11fefe0c633ab061b9f69180593ed9cf073a2 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@gmx.de>
Date: Tue, 17 Jul 2012 02:17:42 +0200
Subject: [PATCH] topng: fix bug causing bogus double insertion of filter alg
 byte

---
 sys/src/cmd/jpg/writepng.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/src/cmd/jpg/writepng.c b/sys/src/cmd/jpg/writepng.c
index f36046e1b..da9d6d374 100644
--- a/sys/src/cmd/jpg/writepng.c
+++ b/sys/src/cmd/jpg/writepng.c
@@ -79,7 +79,7 @@ zread(void *va, void *buf, int n)
 	pixwid = z->pixwid;
 	b = buf;
 	e = b+n;
-	while(b+pixwid <= e){
+	while(b+pixwid < e){	/* one less for filter alg byte */
 		if(z->y >= z->dy)
 			break;
 		if(z->x == 0)