Add missing operators for CFX_WideStringC.

Part 2 of 4.

R=thestig@chromium.org
TBR=brucedawson@chromium.org
BUG=pdfium:142

Review URL: https://codereview.chromium.org/1099193002

2 files changed, 54 insertions, 4 deletions

diff --git a/core/include/fxcrt/fx_string.h b/core/include/fxcrt/fx_string.h
index c1a6ec699e..1efb814b08 100644
--- a/core/include/fxcrt/fx_string.h
+++ b/core/include/fxcrt/fx_string.h
@@ -441,7 +441,7 @@ inline CFX_ByteString operator + (FX_BSTR str1, const CFX_ByteString& str2)
 {
     return CFX_ByteString(str1, str2);
 }
-class CFX_WideStringC 
+class CFX_WideStringC
 {
 public:
     typedef FX_WCHAR value_type;
@@ -563,13 +563,23 @@ public:
         }
         return CFX_WideStringC(m_Ptr + m_Length - count, count);
     }
-protected:
 
-    FX_LPCWSTR		m_Ptr;
+    const FX_WCHAR& operator[] (size_t index) const
+    {
+        return m_Ptr[index];
+    }
+
+    bool operator< (const CFX_WideStringC& that) const
+    {
+        int result = wmemcmp(m_Ptr, that.m_Ptr, std::min(m_Length, that.m_Length));
+        return result < 0 || (result == 0 && m_Length < that.m_Length);
+     }
 
+protected:
+    FX_LPCWSTR		m_Ptr;
     FX_STRSIZE		m_Length;
-private:
 
+private:
     void*			operator new (size_t) throw()
     {
         return NULL;
diff --git a/core/src/fxcrt/fx_basic_wstring_unittest.cpp b/core/src/fxcrt/fx_basic_wstring_unittest.cpp
index 9575dfd786..084410ad19 100644
--- a/core/src/fxcrt/fx_basic_wstring_unittest.cpp
+++ b/core/src/fxcrt/fx_basic_wstring_unittest.cpp
@@ -66,3 +66,43 @@ TEST(fxcrt, WideStringUTF16LE_Encode) {
         << " for case number " << i;
   }
 }
+
+TEST(fxcrt, WideStringCOperatorSubscript) {
+    // CFX_WideStringC includes the NUL terminator for non-empty strings.
+    CFX_WideStringC 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, WideStringCOperatorLT) {
+    CFX_WideStringC empty;
+    CFX_WideStringC a(L"a");
+    CFX_WideStringC abc(L"\x0110qq");  // Comes before despite endianness.
+    CFX_WideStringC 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);
+}
+