Add missing operators for CFX_ByteStringC.

Removing the implicit cast operator forces a build breakage should we
use ByteStringC in STL containers. Adding an operator< restores correct
behaviour. Adding an operator[] avoids re-writing some code to call
GetPtr() prior to array indexing.

Part 1 of 4.

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

Review URL: https://codereview.chromium.org/1090303003

4 files changed, 51 insertions, 12 deletions

diff --git a/core/src/fxcrt/fx_basic_bstring.cpp b/core/src/fxcrt/fx_basic_bstring.cpp
index ea9ca85021..cda7d1fdd7 100644
--- a/core/src/fxcrt/fx_basic_bstring.cpp
+++ b/core/src/fxcrt/fx_basic_bstring.cpp
@@ -276,7 +276,7 @@ bool CFX_ByteString::EqualNoCase(FX_BSTR str) const
         return false;
     }
     FX_LPCBYTE pThis = (FX_LPCBYTE)m_pData->m_String;
-    FX_LPCBYTE pThat = (FX_LPCBYTE)str;
+    FX_LPCBYTE pThat = str.GetPtr();
     for (FX_STRSIZE i = 0; i < len; i ++) {
         if ((*pThis) != (*pThat)) {
             FX_BYTE bThis = *pThis;
diff --git a/core/src/fxcrt/fx_basic_bstring_unittest.cpp b/core/src/fxcrt/fx_basic_bstring_unittest.cpp
index 1ddaad420a..57cfc8047e 100644
--- a/core/src/fxcrt/fx_basic_bstring_unittest.cpp
+++ b/core/src/fxcrt/fx_basic_bstring_unittest.cpp
@@ -229,3 +229,42 @@ TEST(fxcrt, ByteStringCGetAt) {
   EXPECT_EQ('\0', embedded_nul_string.GetAt(2));
   EXPECT_EQ('c', embedded_nul_string.GetAt(3));
 }
+
+TEST(fxcrt, ByteStringCOperatorSubscript) {
+    // CFX_ByteStringC includes the NUL terminator for non-empty strings.
+    CFX_ByteStringC abc("abc");
+    EXPECT_EQ('a', abc[0]);
+    EXPECT_EQ('b', abc[1]);
+    EXPECT_EQ('c', abc[2]);
+    EXPECT_EQ(0, abc[3]);
+}
+
+TEST(fxcrt, ByteStringCOperatorLT) {
+    CFX_ByteStringC empty;
+    CFX_ByteStringC a("a");
+    CFX_ByteStringC abc("abc");
+    CFX_ByteStringC def("def");
+
+    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);
+}
diff --git a/core/src/fxcrt/fx_basic_buffer.cpp b/core/src/fxcrt/fx_basic_buffer.cpp
index bb8466debe..eb5246acec 100644
--- a/core/src/fxcrt/fx_basic_buffer.cpp
+++ b/core/src/fxcrt/fx_basic_buffer.cpp
@@ -143,7 +143,7 @@ CFX_ByteStringC CFX_BinaryBuf::GetByteString() const
 }
 CFX_ByteTextBuf& CFX_ByteTextBuf::operator << (FX_BSTR lpsz)
 {
-    AppendBlock((FX_LPCBYTE)lpsz, lpsz.GetLength());
+    AppendBlock(lpsz.GetPtr(), lpsz.GetLength());
     return *this;
 }
 CFX_ByteTextBuf& CFX_ByteTextBuf::operator << (int i)
@@ -174,7 +174,7 @@ CFX_ByteTextBuf& CFX_ByteTextBuf::operator << (const CFX_ByteTextBuf& buf)
 }
 void CFX_ByteTextBuf::operator =(const CFX_ByteStringC& str)
 {
-    CopyData((FX_LPCBYTE)str, str.GetLength());
+    CopyData(str.GetPtr(), str.GetLength());
 }
 void CFX_WideTextBuf::AppendChar(FX_WCHAR ch)
 {
@@ -285,10 +285,10 @@ CFX_ArchiveSaver& CFX_ArchiveSaver::operator << (FX_BSTR bstr)
     int len = bstr.GetLength();
     if (m_pStream) {
         m_pStream->WriteBlock(&len, sizeof(int));
-        m_pStream->WriteBlock(bstr, len);
+        m_pStream->WriteBlock(bstr.GetPtr(), len);
     } else {
         m_SavingBuf.AppendBlock(&len, sizeof(int));
-        m_SavingBuf.AppendBlock(bstr, len);
+        m_SavingBuf.AppendBlock(bstr.GetPtr(), len);
     }
     return *this;
 }
@@ -488,7 +488,7 @@ FX_INT32 IFX_BufferArchive::AppendDWord(FX_DWORD i)
 }
 FX_INT32 IFX_BufferArchive::AppendString(FX_BSTR lpsz)
 {
-    return AppendBlock((FX_LPCBYTE)lpsz, lpsz.GetLength());
+    return AppendBlock(lpsz.GetPtr(), lpsz.GetLength());
 }
 CFX_FileBufferArchive::CFX_FileBufferArchive(FX_STRSIZE size)
     : IFX_BufferArchive(size)
diff --git a/core/src/fxcrt/fx_basic_maps.cpp b/core/src/fxcrt/fx_basic_maps.cpp
index e85d35e4ac..8ae44ce6a0 100644
--- a/core/src/fxcrt/fx_basic_maps.cpp
+++ b/core/src/fxcrt/fx_basic_maps.cpp
@@ -352,7 +352,7 @@ inline FX_DWORD CFX_MapByteStringToPtr::HashKey(FX_BSTR key) const
 {
     FX_DWORD nHash = 0;
     int len = key.GetLength();
-    FX_LPCBYTE buf = key;
+    FX_LPCBYTE buf = key.GetPtr();
     for (int i = 0; i < len; i ++) {
         nHash = (nHash << 5) + nHash + buf[i];
     }
@@ -518,7 +518,7 @@ void CFX_CMapByteStringToPtr::SetAt(FX_BSTR key, void* value)
     int size = m_Buffer.GetSize();
     for (index = 0; index < size; index ++) {
         _CompactString* pKey = (_CompactString*)m_Buffer.GetAt(index);
-        if (!_CompactStringSame(pKey, (FX_LPCBYTE)key, key_len)) {
+        if (!_CompactStringSame(pKey, key.GetPtr(), key_len)) {
             continue;
         }
         *(void**)(pKey + 1) = value;
@@ -529,19 +529,19 @@ void CFX_CMapByteStringToPtr::SetAt(FX_BSTR key, void* value)
         if (pKey->m_CompactLen) {
             continue;
         }
-        _CompactStringStore(pKey, (FX_LPCBYTE)key, key_len);
+        _CompactStringStore(pKey, key.GetPtr(), key_len);
         *(void**)(pKey + 1) = value;
         return;
     }
     _CompactString* pKey = (_CompactString*)m_Buffer.Add();
-    _CompactStringStore(pKey, (FX_LPCBYTE)key, key_len);
+    _CompactStringStore(pKey, key.GetPtr(), key_len);
     *(void**)(pKey + 1) = value;
 }
 void CFX_CMapByteStringToPtr::AddValue(FX_BSTR key, void* value)
 {
     ASSERT(value != NULL);
     _CompactString* pKey = (_CompactString*)m_Buffer.Add();
-    _CompactStringStore(pKey, (FX_LPCBYTE)key, key.GetLength());
+    _CompactStringStore(pKey, key.GetPtr(), key.GetLength());
     *(void**)(pKey + 1) = value;
 }
 void CFX_CMapByteStringToPtr::RemoveKey(FX_BSTR key)
@@ -550,7 +550,7 @@ void CFX_CMapByteStringToPtr::RemoveKey(FX_BSTR key)
     int size = m_Buffer.GetSize();
     for (int index = 0; index < size; index++) {
         _CompactString* pKey = (_CompactString*)m_Buffer.GetAt(index);
-        if (!_CompactStringSame(pKey, (FX_LPCBYTE)key, key_len)) {
+        if (!_CompactStringSame(pKey, key.GetPtr(), key_len)) {
             continue;
         }
         _CompactStringRelease(pKey);