Added DCHECK() to prevent NULL-pointer dereference

media/audio/win/wavein_input_win.cc

 // Copyright (c) 2012 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 "media/audio/win/wavein_input_win.h"
 
 #pragma comment(lib, "winmm.lib")
 
 #include "base/logging.h"
 #include "media/audio/audio_io.h"
@@ skipping 17 matching lines @@
     AudioManagerWin* manager, const AudioParameters& params, int num_buffers,
     const std::string& device_id)
     : state_(kStateEmpty),
       manager_(manager),
       device_id_(device_id),
       wavein_(NULL),
       callback_(NULL),
       num_buffers_(num_buffers),
       buffer_(NULL),
       channels_(params.channels()) {
+  DCHECK(num_buffers_ > 0);

[James Hawkins, 2012/07/26 17:20:27]

DCHECK_LE(0, num_buffers_)

   format_.wFormatTag = WAVE_FORMAT_PCM;
   format_.nChannels = params.channels() > 2 ? 2 : params.channels();
   format_.nSamplesPerSec = params.sample_rate();
   format_.wBitsPerSample = params.bits_per_sample();
   format_.cbSize = 0;
   format_.nBlockAlign = (format_.nChannels * format_.wBitsPerSample) / 8;
   format_.nAvgBytesPerSec = format_.nBlockAlign * format_.nSamplesPerSec;
   buffer_size_ = params.frames_per_buffer() * format_.nBlockAlign;
   // If we don't have a packet size we use 100ms.
   if (!buffer_size_)
@@ skipping 244 matching lines @@
     }
   } else if (msg == WIM_CLOSE) {
     // We can be closed before calling Start, so it is possible to have a
     // null callback at this point.
     if (obj->callback_)
       obj->callback_->OnClose(obj);
   }
 }
 
 }  // namespace media