Fix some signed/unsigned comparisons in xfa_fm2jscontext.cpp

xfa/fxfa/fm2js/xfa_fm2jscontext.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 "xfa/fxfa/fm2js/xfa_fm2jscontext.h"
 
 #include <time.h>
 
@@ skipping 362 matching lines @@
     15,  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 };
 
 void AlternateDateTimeSymbols(CFX_WideString& wsPattern,
                               const CFX_WideString& wsAltSymbols,
                               const uint8_t* pAltTable) {
   int32_t nLength = wsPattern.GetLength();
   FX_BOOL bInConstRange = FALSE;
   FX_BOOL bEscape = FALSE;
-  int32_t i = 0, n = 0;
+  int32_t i = 0;
+  FX_WCHAR n = 0;
   while (i < nLength) {
     FX_WCHAR wc = wsPattern[i];
     if (wc == L'\'') {
       bInConstRange = !bInConstRange;
       if (bEscape) {
         i++;
       } else {
         wsPattern.Delete(i);
         nLength--;
       }
       bEscape = !bEscape;
       continue;
     }
     if (!bInConstRange && (n = wc - L'A') >= 0 && n <= (L'a' - L'A')) {

[Lei Zhang, 2016/06/01 05:27:04]

How about we get rid of |n| and do:

if (... wc >= L'A' && wc <= L'a') {
  uint8_t nAlt = pAltTable[wc - L'A'];

[Oliver Chang, 2016/06/01 16:08:22]

Done.

-      int32_t nAlt = (int32_t)pAltTable[n];
+      int32_t nAlt = static_cast<int32_t>(pAltTable[n]);

[Lei Zhang, 2016/06/01 05:27:04]

Just make |nAlt| a uint8_t?

[Lei Zhang, 2016/06/01 05:27:04]

BTW, both of the possible tables, |g_sAltTable_Date| and |g_sAltTable_Time|,
seem to have too many entries. Am I right?

[Oliver Chang, 2016/06/01 16:08:22]

Done. Also removed the unused entries (now 33 entries each for both).

       if (nAlt != 255)
         wsPattern.SetAt(i, wsAltSymbols[nAlt]);
     }
     i++;
     bEscape = FALSE;
   }
 }
 
 bool PatternStringType(const CFX_ByteStringC& szPattern,
                        uint32_t& patternType) {
@@ skipping 3812 matching lines @@
       strEncode[2] = strCode[ch - iIndex * 16];
       wsResultBuf << FX_WSTRC(strEncode);
     } else if (ch <= 0x1f || ch == 0x7f) {
       int32_t iIndex = ch / 16;
       strEncode[1] = strCode[iIndex];
       strEncode[2] = strCode[ch - iIndex * 16];
       wsResultBuf << FX_WSTRC(strEncode);
     } else if (ch >= 0x20 && ch <= 0x7e) {
       wsResultBuf.AppendChar(ch);
     } else {
-      int32_t iRadix = 16;
+      FX_WCHAR iRadix = 16;

[Lei Zhang, 2016/06/01 05:27:04]

const?

[Oliver Chang, 2016/06/01 16:08:22]

Done.

       CFX_WideString strTmp;
       while (ch >= iRadix) {
         FX_WCHAR tmp = strCode[ch % iRadix];
         ch /= iRadix;
         strTmp += tmp;
       }
       strTmp += strCode[ch];
       int32_t iLen = strTmp.GetLength();
       if (iLen < 2) {
         break;
@@ skipping 2903 matching lines @@
   CFX_WideString wsFormat;
   pAppProvider->LoadString(iStringID, wsFormat);
   CFX_WideString wsMessage;
   va_list arg_ptr;
   va_start(arg_ptr, iStringID);
   wsMessage.FormatV(wsFormat.c_str(), arg_ptr);
   va_end(arg_ptr);
   FXJSE_ThrowMessage(
       "", FX_UTF8Encode(wsMessage.c_str(), wsMessage.GetLength()).AsStringC());
 }