Use memcpy() instead of violating strict-aliasing rules.

include/opentype-sanitiser.h

 // Copyright (c) 2009 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.
 
 #ifndef OPENTYPE_SANITISER_H_
 #define OPENTYPE_SANITISER_H_
 
 #if defined(_WIN32)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;
@@ skipping 39 matching lines @@
     if (chksum_buffer_offset_) {
       const size_t l =
         std::min(length, static_cast<size_t>(4) - chksum_buffer_offset_);
       std::memcpy(chksum_buffer_ + chksum_buffer_offset_, data, l);
       chksum_buffer_offset_ += l;
       offset += l;
       length -= l;
     }
 
     if (chksum_buffer_offset_ == 4) {
-      // TODO(yusukes): This cast breaks the strict-aliasing rule.
-      chksum_ += ntohl(*reinterpret_cast<const uint32_t*>(chksum_buffer_));
+      uint32_t chksum;
+      std::memcpy(&chksum, chksum_buffer_, 4);
+      chksum_ += ntohl(chksum);
       chksum_buffer_offset_ = 0;
     }
 
     while (length >= 4) {
       chksum_ += ntohl(*reinterpret_cast<const uint32_t*>(
           reinterpret_cast<const uint8_t*>(data) + offset));
       length -= 4;
       offset += 4;
     }
 
@@ skipping 110 matching lines @@
 // -----------------------------------------------------------------------------
 bool Process(OTSStream *output, const uint8_t *input, size_t length);
 
 // Force to disable debug output even when the library is compiled with
 // -DOTS_DEBUG.
 void DisableDebugOutput();
 
 }  // namespace ots
 
 #endif  // OPENTYPE_SANITISER_H_