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

base/file_path_unittest.cc

Index: base/file_path_unittest.cc
diff --git a/base/file_path_unittest.cc b/base/file_path_unittest.cc
index ab2554365216348c0c605ecd5252fd382f262eea..9b23ffc29281d4661ebc857f3d98afa8f8ddc5f1 100644
--- a/base/file_path_unittest.cc
+++ b/base/file_path_unittest.cc
@@ -12,6 +12,9 @@
 // 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;
@@ -1115,6 +1118,40 @@ TEST_F(FilePathTest, FromUTF8Unsafe_And_AsUTF8Unsafe) {
   }
 }
 
+TEST_F(FilePathTest, ConstructWithNUL) {
+  // Assert FPS() works.
+  ASSERT_EQ(FPS("a\0b").length(), 3);
+
+  // Test constructor strips '\0'
+  FilePath path(FPS("a\0b"));
+  EXPECT_EQ(path.value().length(), 1);
+  EXPECT_EQ(path.value(), FPL("a"));
+}
+
+TEST_F(FilePathTest, AppendWithNUL) {
+  // Assert FPS() works.
+  ASSERT_EQ(FPS("b\0b").length(), 3);
+
+  // Test Append() strips '\0'
+  FilePath path(FPL("a"));
+  path = path.Append(FPS("b\0b"));
+  EXPECT_EQ(path.value().length(), 3);
+#if defined(FILE_PATH_USES_WIN_SEPARATORS)
+  EXPECT_EQ(path.value(), "a\\b");
+#else
+  EXPECT_EQ(path.value(), "a/b");
+#endif
+}
+
+TEST_F(FilePathTest, ReferencesParentWithNUL) {
+  // Assert FPS() works.
+  ASSERT_EQ(FPS("..\0").length(), 3);
+
+  // Test ReferencesParent() doesn't break with "..\0"
+  FilePath path(FPS("..\0"));
+  EXPECT_TRUE(path.ReferencesParent());
+}
+
 #if defined(FILE_PATH_USES_WIN_SEPARATORS)
 TEST_F(FilePathTest, NormalizePathSeparators) {
   const struct UnaryTestData cases[] = {