Properly handle zero-sized fields in the PReg parser.

chrome/browser/policy/preg_parser_win_unittest.cc

 // Copyright (c) 2013 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/browser/policy/preg_parser_win.h"
 
 #include "base/base_paths.h"
 #include "base/files/file_path.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
@@ skipping 25 matching lines @@
       return result;
   }
 
   RegistryDict::ValueMap::const_iterator iter_value_a(a.values().begin());
   RegistryDict::ValueMap::const_iterator iter_value_b(b.values().begin());
   for (; iter_value_a != a.values().end() && iter_value_b != b.values().end();
        ++iter_value_a, ++iter_value_b) {
     if (iter_value_a->first != iter_value_b->first ||
         !base::Value::Equals(iter_value_a->second, iter_value_b->second)) {
       return testing::AssertionFailure()
-          << "Value mismatch " << iter_value_a->first
-          << " vs. " << iter_value_b->first;
+          << "Value mismatch "
+          << iter_value_a->first << "=" << *iter_value_a->second
+          << " vs. " << iter_value_b->first << "=" << *iter_value_b->second;
     }
   }
 
   return testing::AssertionSuccess();
 }
 
 void SetInteger(RegistryDict* dict,
                 const std::string& name,
                 int value) {
   dict->SetValue(
@@ skipping 43 matching lines @@
   expected.SetKey("DelValsTest", del_vals_dict.Pass());
   SetInteger(&expected, "HomepageIsNewTabPage", 1);
   SetString(&expected, "HomepageLocation", "http://www.example.com");
   SetInteger(&expected, "RestoreOnStartup", 4);
   scoped_ptr<RegistryDict> startup_urls(new RegistryDict());
   SetString(startup_urls.get(), "1", "http://www.chromium.org");
   SetString(startup_urls.get(), "2", "http://www.example.com");
   expected.SetKey("RestoreOnStartupURLs", startup_urls.Pass());
   SetInteger(&expected, "ShowHomeButton", 1);
   SetString(&expected, "Snowman", "\xE2\x98\x83");
+  SetString(&expected, "Empty", "");
 
   EXPECT_TRUE(RegistryDictEquals(dict, expected));
 }
 
 }  // namespace
 }  // namespace preg_parser
 }  // namespace policy