2 files changed, 73 insertions, 29 deletions
diff --git a/core/include/fxcrt/fx_string.h b/core/include/fxcrt/fx_string.h
index 4db83e3914..dd8752ef28 100644
--- a/core/include/fxcrt/fx_string.h
+++ b/core/include/fxcrt/fx_string.h
@@ -654,6 +654,11 @@ public:
 
     const CFX_WideString&	operator += (const CFX_WideStringC& str);
 
+    bool operator< (const CFX_WideString& str) const {
+        int result = wmemcmp(c_str(), str.c_str(), std::min(GetLength(), str.GetLength()));
+        return result < 0 || (result == 0 && GetLength() < str.GetLength());
+    }
+
     FX_WCHAR				GetAt(FX_STRSIZE nIndex) const
     {
         return m_pData ? m_pData->m_String[nIndex] : 0;
diff --git a/core/src/fxcrt/fx_basic_wstring_unittest.cpp b/core/src/fxcrt/fx_basic_wstring_unittest.cpp
index c6e5c2f3d0..9575dfd786 100644
--- a/core/src/fxcrt/fx_basic_wstring_unittest.cpp
+++ b/core/src/fxcrt/fx_basic_wstring_unittest.cpp
@@ -1,29 +1,68 @@
-// Copyright 2014 PDFium 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 "testing/gtest/include/gtest/gtest.h"
-#include "../../../testing/fx_string_testhelpers.h"
-#include "../../include/fxcrt/fx_basic.h"
-
-#define ByteStringLiteral(str) CFX_ByteString(FX_BSTRC(str))
-
-TEST(fxcrt, WideStringUTF16LE_Encode) {
-  struct UTF16LEEncodeCase {
-    CFX_WideString ws;
-    CFX_ByteString bs;
-  } utf16le_encode_cases[] = {
-    { L"", ByteStringLiteral("\0\0") },
-    { L"abc", ByteStringLiteral("a\0b\0c\0\0\0") },
-    { L"abcdef", ByteStringLiteral("a\0b\0c\0d\0e\0f\0\0\0") },
-    { L"abc\0def", ByteStringLiteral("a\0b\0c\0\0\0") },
-    { L"\xaabb\xccdd", ByteStringLiteral("\xbb\xaa\xdd\xcc\0\0") },
-    { L"\x3132\x6162", ByteStringLiteral("\x32\x31\x62\x61\0\0") },
-  };
-
-  for (size_t i = 0; i < FX_ArraySize(utf16le_encode_cases); ++i) {
-    EXPECT_EQ(utf16le_encode_cases[i].bs,
-        utf16le_encode_cases[i].ws.UTF16LE_Encode())
-        << " for case number " << i;
-  }
-}
+// Copyright 2014 PDFium 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 "testing/gtest/include/gtest/gtest.h"
+#include "../../../testing/fx_string_testhelpers.h"
+#include "../../include/fxcrt/fx_basic.h"
+
+TEST(fxcrt, WideStringOperatorSubscript) {
+    // CFX_WideString includes the NUL terminator for non-empty strings.
+    CFX_WideString abc(L"abc");
+    EXPECT_EQ(L'a', abc[0]);
+    EXPECT_EQ(L'b', abc[1]);
+    EXPECT_EQ(L'c', abc[2]);
+    EXPECT_EQ(L'\0', abc[3]);
+}
+
+TEST(fxcrt, WideStringOperatorLT) {
+    CFX_WideString empty;
+    CFX_WideString a(L"a");
+    CFX_WideString abc(L"\x0110qq");  // Comes before despite endianness.
+    CFX_WideString def(L"\x1001qq");  // Comes after despite endianness.
+
+    EXPECT_FALSE(empty < empty);
+    EXPECT_FALSE(a < a);
+    EXPECT_FALSE(abc < abc);
+    EXPECT_FALSE(def < def);
+
+    EXPECT_TRUE(empty < a);
+    EXPECT_FALSE(a < empty);
+
+    EXPECT_TRUE(empty < abc);
+    EXPECT_FALSE(abc < empty);
+
+    EXPECT_TRUE(empty < def);
+    EXPECT_FALSE(def < empty);
+
+    EXPECT_TRUE(a < abc);
+    EXPECT_FALSE(abc < a);
+
+    EXPECT_TRUE(a < def);
+    EXPECT_FALSE(def < a);
+
+    EXPECT_TRUE(abc < def);
+    EXPECT_FALSE(def < abc);
+}
+
+#define ByteStringLiteral(str) CFX_ByteString(FX_BSTRC(str))
+
+TEST(fxcrt, WideStringUTF16LE_Encode) {
+  struct UTF16LEEncodeCase {
+    CFX_WideString ws;
+    CFX_ByteString bs;
+  } utf16le_encode_cases[] = {
+    { L"", ByteStringLiteral("\0\0") },
+    { L"abc", ByteStringLiteral("a\0b\0c\0\0\0") },
+    { L"abcdef", ByteStringLiteral("a\0b\0c\0d\0e\0f\0\0\0") },
+    { L"abc\0def", ByteStringLiteral("a\0b\0c\0\0\0") },
+    { L"\xaabb\xccdd", ByteStringLiteral("\xbb\xaa\xdd\xcc\0\0") },
+    { L"\x3132\x6162", ByteStringLiteral("\x32\x31\x62\x61\0\0") },
+  };
+
+  for (size_t i = 0; i < FX_ArraySize(utf16le_encode_cases); ++i) {
+    EXPECT_EQ(utf16le_encode_cases[i].bs,
+        utf16le_encode_cases[i].ws.UTF16LE_Encode())
+        << " for case number " << i;
+  }
+}