From 16ee636a58c7e0eb1e44b85681ea61fd692fef7f Mon Sep 17 00:00:00 2001
From: Uoti Urpala <uau@glyph.nonexistent.invalid>
Date: Tue, 26 Jan 2010 16:38:39 +0200
Subject: [PATCH] demux_mkv: don't print errors for 0-size zlib decoding

Allow decoding a 0-sized buffer with zlib algorithm to produce 0-sized
output. Fixes spurious errors reported with subtitle tracks marked to
use compression for track private data without having any such data.
---
 libmpdemux/demux_mkv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libmpdemux/demux_mkv.c b/libmpdemux/demux_mkv.c
index 00dfe3ae08..982f04062d 100644
--- a/libmpdemux/demux_mkv.c
+++ b/libmpdemux/demux_mkv.c
@@ -326,6 +326,10 @@ static int demux_mkv_decode(mkv_track_t *track, uint8_t *src,
 #if CONFIG_ZLIB
         if (track->encodings[i].comp_algo == 0) {
             /* zlib encoded track */
+
+            if (*size == 0)
+                continue;
+
             z_stream zstream;
 
             zstream.zalloc = (alloc_func) 0;