Update woff2 to 4e698b8

third_party/woff2/src/woff2_common.cc

 // Copyright 2013 Google Inc. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 // http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
 // Helpers common across multiple parts of woff2
 
 #include <algorithm>
 
 #include "./woff2_common.h"
 
 namespace woff2 {
 
 
 uint32_t ComputeULongSum(const uint8_t* buf, size_t size) {
   uint32_t checksum = 0;
-  for (size_t i = 0; i < size; i += 4) {
+  size_t aligned_size = size & ~3;
+  for (size_t i = 0; i < aligned_size; i += 4) {
 #if (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
     uint32_t v = *reinterpret_cast<const uint32_t*>(buf + i);
     checksum += (((v & 0xFF) << 24) | ((v & 0xFF00) << 8) |
       ((v & 0xFF0000) >> 8) | ((v & 0xFF000000) >> 24));
 #elif (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
     checksum += *reinterpret_cast<const uint32_t*>(buf + i);
 #else
     checksum += (buf[i] << 24) | (buf[i + 1] << 16) |
       (buf[i + 2] << 8) | buf[i + 3];
 #endif
   }
+
+  // treat size not aligned on 4 as if it were padded to 4 with 0's
+  if (size != aligned_size) {
+    uint32_t v = 0;
+    for (size_t i = aligned_size; i < size; ++i) {
+      v |= buf[i] << (24 - 8 * (i & 3));
+    }
+    checksum += v;
+  }
+
   return checksum;
 }
 
 size_t CollectionHeaderSize(uint32_t header_version, uint32_t num_fonts) {
   size_t size = 0;
   if (header_version == 0x00020000) {
     size += 12;  // ulDsig{Tag,Length,Offset}
   }
   if (header_version == 0x00010000 || header_version == 0x00020000) {
     size += 12   // TTCTag, Version, numFonts
       + 4 * num_fonts;  // OffsetTable[numFonts]
   }
   return size;
 }
 
 } // namespace woff2