Fix for left-shift of potentially negative values in NetEq.

webrtc/modules/audio_coding/neteq/expand.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 423 matching lines @@
   WebRtcSpl_VectorBitShiftW32ToW16(best_distortion, kNumCorrelationCandidates,
                                    best_distortion_w32, distortion_scale);
 
   // Find the maximizing index |i| of the cost function
   // f[i] = best_correlation[i] / best_distortion[i].
   int32_t best_ratio = std::numeric_limits<int32_t>::min();
   size_t best_index = std::numeric_limits<size_t>::max();
   for (size_t i = 0; i < kNumCorrelationCandidates; ++i) {
     int32_t ratio;
     if (best_distortion[i] > 0) {
-      ratio = (best_correlation[i] << 16) / best_distortion[i];
+      ratio = (best_correlation[i] * (1 << 16)) / best_distortion[i];
     } else if (best_correlation[i] == 0) {
       ratio = 0;  // No correlation set result to zero.
     } else {
       ratio = std::numeric_limits<int32_t>::max();  // Denominator is zero.
     }
     if (ratio > best_ratio) {
       best_index = i;
       best_ratio = ratio;
     }
   }
@@ skipping 514 matching lines @@
   const size_t kMaxRandSamples = RandomVector::kRandomTableSize;
   while (samples_generated < length) {
     size_t rand_length = std::min(length - samples_generated, kMaxRandSamples);
     random_vector_->IncreaseSeedIncrement(seed_increment);
     random_vector_->Generate(rand_length, &random_vector[samples_generated]);
     samples_generated += rand_length;
   }
 }
 
 }  // namespace webrtc