Fix fuzzer crash for preg_parser

components/policy/core/common/preg_parser_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 "components/policy/core/common/preg_parser.h"
 
 #include <utility>
 
 #include "base/base_paths.h"
 #include "base/files/file_path.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "components/policy/core/common/policy_load_status.h"
 #include "components/policy/core/common/registry_dict.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace policy {
 namespace preg_parser {
 namespace {
 
-const char kRegistryPolFile[] = "chrome/test/data/policy/registry.pol";
+// Preg files are relative to |kRegistryPolBaseDir|.
+const char kRegistryPolBaseDir[] = "chrome/test/data/policy/gpo";
+const char kRegistryPolFile[] = "parser_test/registry.pol";
+const char kInvalidEncodingRegistryPolFile[] = "invalid_encoding/registry.pol";
+
 const char kRegistryKey[] = "SOFTWARE\\Policies\\Chromium";
 
 // Check whether two RegistryDicts equal each other.
 testing::AssertionResult RegistryDictEquals(const RegistryDict& a,
                                             const RegistryDict& b) {
   auto iter_key_a = a.keys().begin();
   auto iter_key_b = b.keys().begin();
   for (; iter_key_a != a.keys().end() && iter_key_b != b.keys().end();
        ++iter_key_a, ++iter_key_b) {
     if (iter_key_a->first != iter_key_b->first) {
@@ skipping 40 matching lines @@
 void SetInteger(RegistryDict* dict, const std::string& name, int value) {
   dict->SetValue(name, base::WrapUnique<base::Value>(new base::Value(value)));
 }
 
 void SetString(RegistryDict* dict,
                const std::string& name,
                const std::string& value) {
   dict->SetValue(name, base::WrapUnique<base::Value>(new base::Value(value)));
 }
 
-TEST(PRegParserTest, TestParseFile) {
-  base::FilePath test_data_dir;
-  ASSERT_TRUE(PathService::Get(base::DIR_SOURCE_ROOT, &test_data_dir));
+class PRegParserTest : public testing::Test {
+ protected:
+  void SetUp() override {
+    ASSERT_TRUE(PathService::Get(base::DIR_SOURCE_ROOT, &test_data_dir_));
+    test_data_dir_ = test_data_dir_.AppendASCII(kRegistryPolBaseDir);
+  }
 
+  base::FilePath test_data_dir_;
+};
+
+TEST_F(PRegParserTest, TestParseFile) {
   // Prepare the test dictionary with some data so the test can check that the
   // PReg action triggers work, i.e. remove these items.
   RegistryDict dict;
   SetInteger(&dict, "DeleteValuesTest1", 1);
   SetString(&dict, "DeleteValuesTest2", "2");
   dict.SetKey("DeleteKeysTest1", base::MakeUnique<RegistryDict>());
   std::unique_ptr<RegistryDict> delete_keys_test(new RegistryDict());
   SetInteger(delete_keys_test.get(), "DeleteKeysTest2Entry", 1);
   dict.SetKey("DeleteKeysTest2", std::move(delete_keys_test));
   SetInteger(&dict, "DelTest", 1);
   std::unique_ptr<RegistryDict> subdict(new RegistryDict());
   SetInteger(subdict.get(), "DelValsTest1", 1);
   SetString(subdict.get(), "DelValsTest2", "2");
   subdict->SetKey("DelValsTest3", base::MakeUnique<RegistryDict>());
   dict.SetKey("DelValsTest", std::move(subdict));
 
   // Run the parser.
-  base::FilePath test_file(test_data_dir.AppendASCII(kRegistryPolFile));
+  base::FilePath test_file(test_data_dir_.AppendASCII(kRegistryPolFile));
   PolicyLoadStatusSample status;
   ASSERT_TRUE(preg_parser::ReadFile(test_file, base::ASCIIToUTF16(kRegistryKey),
                                     &dict, &status));
 
   // Build the expected output dictionary.
   RegistryDict expected;
   std::unique_ptr<RegistryDict> del_vals_dict(new RegistryDict());
   del_vals_dict->SetKey("DelValsTest3", base::MakeUnique<RegistryDict>());
   expected.SetKey("DelValsTest", std::move(del_vals_dict));
   SetInteger(&expected, "HomepageIsNewTabPage", 1);
   SetString(&expected, "HomepageLocation", "http://www.example.com");
   SetInteger(&expected, "RestoreOnStartup", 4);
   std::unique_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", std::move(startup_urls));
   SetInteger(&expected, "ShowHomeButton", 1);
   SetString(&expected, "Snowman", "\xE2\x98\x83");
   SetString(&expected, "Empty", "");
 
   EXPECT_TRUE(RegistryDictEquals(dict, expected));
 }
 
-TEST(PRegParserTest, SubstringRootInvalid) {
+TEST_F(PRegParserTest, SubstringRootInvalid) {
   // A root of "Aa/Bb/Cc" should not be considered a valid root for a
   // key like "Aa/Bb/C".
-  base::FilePath test_data_dir;
-  ASSERT_TRUE(PathService::Get(base::DIR_SOURCE_ROOT, &test_data_dir));
-
-  base::FilePath test_file(test_data_dir.AppendASCII(kRegistryPolFile));
+  base::FilePath test_file(test_data_dir_.AppendASCII(kRegistryPolFile));
   RegistryDict empty;
   PolicyLoadStatusSample status;
 
   // No data should be loaded for partial roots ("Aa/Bb/C").
   RegistryDict dict1;
   ASSERT_TRUE(preg_parser::ReadFile(
       test_file, base::ASCIIToUTF16("SOFTWARE\\Policies\\Chro"), &dict1,
       &status));
   EXPECT_TRUE(RegistryDictEquals(dict1, empty));
 
   // Safety check with kRegistryKey (dict should not be empty).
   RegistryDict dict2;
   ASSERT_TRUE(preg_parser::ReadFile(test_file, base::ASCIIToUTF16(kRegistryKey),
                                     &dict2, &status));
   EXPECT_FALSE(RegistryDictEquals(dict2, empty));
 }
 
+TEST_F(PRegParserTest, RejectInvalidStrings) {
+  // Tests whether strings with invalid characters are rejected.
+  base::FilePath test_file(
+      test_data_dir_.AppendASCII(kInvalidEncodingRegistryPolFile));
+  PolicyLoadStatusSample status;
+  RegistryDict dict;
+  ASSERT_TRUE(preg_parser::ReadFile(test_file, base::ASCIIToUTF16(kRegistryKey),
+                                    &dict, &status));
+
+  RegistryDict empty;
+  EXPECT_TRUE(RegistryDictEquals(dict, empty));
+}
+
 }  // namespace
 }  // namespace preg_parser
 }  // namespace policy