From a99dbe014dbd01b227f97e7d7f0f72b3ae4f9be0 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
Date: Wed, 7 Dec 2011 11:31:27 +0100
Subject: [PATCH] Do not ignore full transparency when writing png palette.

This reverts r6689, "Make PNG produce correct 8-bit pictures".
---
 libavcodec/pngenc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/pngenc.c b/libavcodec/pngenc.c
index 29f4e1a0df..b35402eddf 100644
--- a/libavcodec/pngenc.c
+++ b/libavcodec/pngenc.c
@@ -336,7 +336,7 @@ static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size,
         for(i = 0; i < 256; i++) {
             v = palette[i];
             alpha = v >> 24;
-            if (alpha && alpha != 0xff)
+            if (alpha != 0xff)
                 has_alpha = 1;
             *alpha_ptr++ = alpha;
             bytestream_put_be24(&ptr, v);