Don't allow '\0' characters in FilePath.

base/file_path_unittest.cc

 // Copyright (c) 2012 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 "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
 // This macro helps avoid wrapped lines in the test structs.
 #define FPL(x) FILE_PATH_LITERAL(x)
 
+// This macro constructs strings which can contain NULs.
+#define FPS(x) FilePath::StringType(FPL(x), arraysize(FPL(x)) - 1)
+
 struct UnaryTestData {
   const FilePath::CharType* input;
   const FilePath::CharType* expected;
 };
 
 struct UnaryBooleanTestData {
   const FilePath::CharType* input;
   bool expected;
 };
 
@@ skipping 1083 matching lines @@
         << "i: " << i << ", input: " << cases[i].native;
     // Test AsUTF8Unsafe() works.
     FilePath from_native = FilePath(cases[i].native);
     EXPECT_EQ(cases[i].utf8, from_native.AsUTF8Unsafe())
         << "i: " << i << ", input: " << cases[i].native;
     // Test the two file paths are identical.
     EXPECT_EQ(from_utf8.value(), from_native.value());
   }
 }
 
+// Test constructor strips '\0'
+TEST_F(FilePathTest, ConstructWithNUL) {
+  FilePath path(FPS("a\0b"));
+  EXPECT_EQ(path.value(), FPL("a"));

[Chris Evans, 2013/01/08 09:41:01]

I'm not 100% sure how std::string equality works. If it's similar to a strcmp(),
you might not be testing what you were hoping to test.

To be safe, I think you'll want to check that path.value().length() == 1. You
might also want to throw in a check that FilePath::StringType
s(FPS("a\0b")).length() == 3, to prove you macro is working :)

+}
+
+// Test Append() strips '\0'
+TEST_F(FilePathTest, AppendWithNUL) {
+  FilePath path(FPL("a"));
+  path = path.Append(FPS("b\0b"));
+#if defined(FILE_PATH_USES_WIN_SEPARATORS)
+  EXPECT_EQ(path.value(), "a\\b");
+#else
+  EXPECT_EQ(path.value(), "a/b");

[Chris Evans, 2013/01/08 09:41:01]

Again, maybe check length() to be sure.

+#endif
+}
+
+// Test ReferencesParent() doesn't break with "..\0"
+TEST_F(FilePathTest, ReferencesParentWithNUL) {
+  FilePath path(FPS("..\0"));
+  ASSERT_TRUE(path.ReferencesParent());
+}
+
 #if defined(FILE_PATH_USES_WIN_SEPARATORS)
 TEST_F(FilePathTest, NormalizePathSeparators) {
   const struct UnaryTestData cases[] = {
     { FPL("foo/bar"), FPL("foo\\bar") },
     { FPL("foo/bar\\betz"), FPL("foo\\bar\\betz") },
     { FPL("foo\\bar"), FPL("foo\\bar") },
     { FPL("foo\\bar/betz"), FPL("foo\\bar\\betz") },
     { FPL("foo"), FPL("foo") },
     // Trailing slashes don't automatically get stripped.  That's what
     // StripTrailingSeparators() is for.
@@ skipping 24 matching lines @@
   };
   for (size_t i = 0; i < arraysize(cases); ++i) {
     FilePath input(cases[i].input);
     FilePath observed = input.NormalizePathSeparators();
     EXPECT_EQ(FilePath::StringType(cases[i].expected), observed.value()) <<
               "i: " << i << ", input: " << input.value();
   }
 }
 
 #endif