From: Xijian Yan <yanxijian@163.com>
Date: Mon, 6 Nov 2017 15:48:17 +0000 (+0800)
Subject: Fix crash when loading an empty mpeg file (#830)
X-Git-Tag: v1.12-beta-1~38
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=249f892455d2759d45a6f5976f03924c04910411;p=taglib

Fix crash when loading an empty mpeg file (#830)

When loading an empty file (empty.txt -> empty.mp3 ), TagLib will crash.
buffer.size() is 0, then buffer.size() - 1 is undefined (unsigned int)
---

diff --git a/taglib/mpeg/mpegfile.cpp b/taglib/mpeg/mpegfile.cpp
index 217b03dd..517aea56 100644
--- a/taglib/mpeg/mpegfile.cpp
+++ b/taglib/mpeg/mpegfile.cpp
@@ -108,6 +108,9 @@ bool MPEG::File::isSupported(IOStream *stream)
   long headerOffset;
   const ByteVector buffer = Utils::readHeader(stream, bufferSize(), true, &headerOffset);
 
+  if(buffer.isEmpty())
+	  return false;
+  
   const long originalPosition = stream->tell();
   AdapterFile file(stream);