Simplify UTF16LE_Encode and add unittest.

core/src/fxcrt/fx_basic_wstring.cpp

 // 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.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../include/fxcrt/fx_basic.h"
 #include "../../../third_party/numerics/safe_math.h"
 
 static CFX_StringDataW* FX_AllocStringW(int nLen)
@@ skipping 305 matching lines @@
 {
     if (m_pData == NULL) {
         return (lpsz == NULL || lpsz[0] == 0) ? 0 : -1;
     }
     return FXSYS_wcscmp(m_pData->m_String, lpsz);
 }
 CFX_ByteString CFX_WideString::UTF8Encode() const
 {
     return FX_UTF8Encode(*this);
 }
-CFX_ByteString CFX_WideString::UTF16LE_Encode(FX_BOOL bTerminate) const
+CFX_ByteString CFX_WideString::UTF16LE_Encode() const
 {
     if (m_pData == NULL) {
-        return bTerminate ? CFX_ByteString(FX_BSTRC("\0\0")) : CFX_ByteString();
+        return CFX_ByteString(FX_BSTRC("\0\0"));
     }
     int len = m_pData->m_nDataLength;
     CFX_ByteString result;
-    FX_LPSTR buffer = result.GetBuffer(len * 2 + (bTerminate ? 2 : 0));
+    FX_LPSTR buffer = result.GetBuffer(len * 2 + 2);
     for (int i = 0; i < len; i ++) {
         buffer[i * 2] = m_pData->m_String[i] & 0xff;
         buffer[i * 2 + 1] = m_pData->m_String[i] >> 8;
     }
-    if (bTerminate) {
-        buffer[len * 2] = 0;
-        buffer[len * 2 + 1] = 0;
-        result.ReleaseBuffer(len * 2 + 2);
-    } else {
-        result.ReleaseBuffer(len * 2);
-    }
+    buffer[len * 2] = 0;
+    buffer[len * 2 + 1] = 0;
+    result.ReleaseBuffer(len * 2 + 2);
     return result;
 }
 void CFX_WideString::ConvertFrom(const CFX_ByteString& str, CFX_CharMap* pCharMap)
 {
     if (pCharMap == NULL) {
         pCharMap = CFX_CharMap::GetDefaultMapper();
     }
     *this = pCharMap->m_GetWideString(pCharMap, str);
 }
 void CFX_WideString::Reserve(FX_STRSIZE len)
@@ skipping 765 matching lines @@
             return (CFX_CharMap*)&g_DefaultJISMapper;
         case 936:
             return (CFX_CharMap*)&g_DefaultGBKMapper;
         case 949:
             return (CFX_CharMap*)&g_DefaultUHCMapper;
         case 950:
             return (CFX_CharMap*)&g_DefaultBig5Mapper;
     }
     return NULL;
 }