Return 0 instead of AVERROR_EOF for reads at or past the end of a file.

media/filters/ffmpeg_demuxer.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/scoped_ptr.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
@@ skipping 318 matching lines @@
 }
 
 int FFmpegDemuxer::Read(int size, uint8* data) {
   DCHECK(data_source_);
 
   // If read has ever failed, return with an error.
   // TODO(hclam): use a more meaningful constant as error.
   if (read_has_failed_)
     return AVERROR_IO;
 
-  // If the read position exceeds the size of the data source. We should return
-  // end-of-file directly.
+  // Even though FFmpeg defines AVERROR_EOF, it's not to be used with I/O
+  // routines.  Instead return 0 for any read at or past EOF.
   int64 file_size;
   if (data_source_->GetSize(&file_size) && read_position_ >= file_size)
-    return AVERROR_EOF;
+    return 0;
 
   // Asynchronous read from data source.
   data_source_->Read(read_position_, size, data,
                      NewCallback(this, &FFmpegDemuxer::OnReadCompleted));
 
   // TODO(hclam): The method is called on the demuxer thread and this method
   // call will block the thread. We need to implemented an additional thread to
   // let FFmpeg demuxer methods to run on.
   size_t last_read_bytes = WaitForRead();
   if (last_read_bytes == DataSource::kReadError) {
@@ skipping 266 matching lines @@
   read_event_.Wait();
   return last_read_bytes_;
 }
 
 void FFmpegDemuxer::SignalReadCompleted(size_t size) {
   last_read_bytes_ = size;
   read_event_.Signal();
 }
 
 }  // namespace media