Fix some signed/unsigned comparisons in xfa_fm2jscontext.cpp

xfa/fxfa/fm2js/xfa_fm2jscontext.cpp

Index: xfa/fxfa/fm2js/xfa_fm2jscontext.cpp
diff --git a/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp b/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp
index e778d429948df19ebcaa50d4e3e25203666f74fe..9768b16116f260c4efcc6ec2c3ab9c8f8032547d 100644
--- a/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp
+++ b/xfa/fxfa/fm2js/xfa_fm2jscontext.cpp
@@ -380,7 +380,8 @@ void AlternateDateTimeSymbols(CFX_WideString& wsPattern,
   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'\'') {
@@ -395,7 +396,7 @@ void AlternateDateTimeSymbols(CFX_WideString& wsPattern,
       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]);
     }
@@ -4228,7 +4229,7 @@ void CXFA_FM2JSContext::EncodeURL(const CFX_ByteStringC& szURLString,
     } 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];