Make string_util::WriteInto() DCHECK() that the supplied |length_with_null| > 1, meaning that the...

net/disk_cache/entry_impl.cc

 // Copyright (c) 2011 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 "net/disk_cache/entry_impl.h"
 
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "net/base/io_buffer.h"
@@ skipping 755 matching lines @@
   Addr address(entry->Data()->long_key);
   DCHECK(address.is_initialized());
   size_t offset = 0;
   if (address.is_block_file())
     offset = address.start_block() * address.BlockSize() + kBlockHeaderSize;
 
   COMPILE_ASSERT(kNumStreams == kKeyFileIndex, invalid_key_index);
   File* key_file = const_cast<EntryImpl*>(this)->GetBackingFile(address,
                                                                 kKeyFileIndex);
 
-  if (!offset && key_file->GetLength() != static_cast<size_t>(key_len + 1))
+  ++key_len;  // We store a trailing \0 on disk that we read back below.
+  if (!offset && key_file->GetLength() != static_cast<size_t>(key_len))
     return std::string();
 
-  if (!key_file ||
-      !key_file->Read(WriteInto(&key_, key_len + 1), key_len + 1, offset))
+  if (!key_file || !key_file->Read(WriteInto(&key_, key_len), key_len, offset))
     key_.clear();
   return key_;
 }
 
 Time EntryImpl::GetLastUsed() const {
   CacheRankingsBlock* node = const_cast<CacheRankingsBlock*>(&node_);
   return Time::FromInternalValue(node->Data()->last_used);
 }
 
 Time EntryImpl::GetLastModified() const {
@@ skipping 701 matching lines @@
   Trace("%s 0x%p 0x%x 0x%x", msg, reinterpret_cast<void*>(this),
         entry_.address().value(), node_.address().value());
 
   Trace("  data: 0x%x 0x%x 0x%x", entry_.Data()->data_addr[0],
         entry_.Data()->data_addr[1], entry_.Data()->long_key);
 
   Trace("  doomed: %d 0x%x", doomed_, dirty);
 }
 
 }  // namespace disk_cache