Fix race in directory creation on Windows. The...

base/file_util_unittest.cc

 // Copyright (c) 2009 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 "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #include <shlobj.h>
@@ skipping 1119 matching lines @@
   // Doesn't work to create it on top of a non-dir
   test_path = test_path.Append(FILE_PATH_LITERAL("foobar.txt"));
   EXPECT_FALSE(file_util::PathExists(test_path));
   CreateTextFile(test_path, L"test file");
   EXPECT_TRUE(file_util::PathExists(test_path));
   EXPECT_FALSE(file_util::CreateDirectory(test_path));
 
   EXPECT_TRUE(file_util::Delete(test_root, true));
   EXPECT_FALSE(file_util::PathExists(test_root));
   EXPECT_FALSE(file_util::PathExists(test_path));
+
+  // Verify assumptions made by the Windows implementation:
+  // 1. The current directory always exists.
+  // 2. The root directory always exists.
+  ASSERT_TRUE(file_util::DirectoryExists(
+      FilePath(FilePath::kCurrentDirectory)));
+  FilePath top_level = test_root;
+  while (top_level != top_level.DirName()) {
+    top_level = top_level.DirName();
+  }
+  ASSERT_TRUE(file_util::DirectoryExists(top_level));
+
+  // Given these assumptions hold, it should be safe to
+  // test that "creating" these directories succeeds.
+  EXPECT_TRUE(file_util::CreateDirectory(
+      FilePath(FilePath::kCurrentDirectory)));
+  EXPECT_TRUE(file_util::CreateDirectory(top_level));
 }
 
 TEST_F(FileUtilTest, DetectDirectoryTest) {
   // Check a directory
   FilePath test_root =
       test_dir_.Append(FILE_PATH_LITERAL("detect_directory_test"));
   EXPECT_FALSE(file_util::PathExists(test_root));
   EXPECT_TRUE(file_util::CreateDirectory(test_root));
   EXPECT_TRUE(file_util::PathExists(test_root));
   EXPECT_TRUE(file_util::DirectoryExists(test_root));
@@ skipping 205 matching lines @@
 #elif defined(OS_LINUX)
   EXPECT_FALSE(file_util::ContainsPath(foo,
       foo_caps.Append(FILE_PATH_LITERAL("bar.txt"))));
 #else
   // We can't really do this test on osx since the case-sensitivity of the
   // filesystem is configurable.
 #endif
 }
 
 }  // namespace