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

chrome/common/metrics_log_manager.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 "chrome/common/metrics_log_manager.h"
 
 #if defined(USE_SYSTEM_LIBBZ2)
 #include <bzlib.h>
 #else
 #include "third_party/bzip2/bzlib.h"
@@ skipping 87 matching lines @@
   DCHECK(log_serializer_.get());
   if (!log_serializer_.get())
     return;
   log_serializer_->DeserializeLogs(INITIAL_LOG, &unsent_initial_logs_);
   log_serializer_->DeserializeLogs(ONGOING_LOG, &unsent_ongoing_logs_);
 }
 
 void MetricsLogManager::CompressStagedLog() {
   int text_size = staged_log_->GetEncodedLogSize();
   std::string staged_log_text;
-  // Leave room for the NULL terminator.
+  DCHECK_GT(text_size, 0);
   staged_log_->GetEncodedLog(WriteInto(&staged_log_text, text_size + 1),
                              text_size);
 
   bool success = Bzip2Compress(staged_log_text, &compressed_staged_log_text_);
   if (success) {
     // Allow security-conscious users to see all metrics logs that we send.
     VLOG(1) << "METRICS LOG: " << staged_log_text;
   } else {
     LOG(DFATAL) << "Failed to compress log for transmission.";
   }
@@ skipping 34 matching lines @@
     // TODO(jar): See if it would be better to do a CHECK() here.
     return false;
   }
   result = BZ2_bzCompressEnd(&stream);
   DCHECK(result == BZ_OK);
 
   output->resize(stream.total_out_lo32);
 
   return true;
 }