Revert "Revert "Revert "Revert "Cleanup some numeric code.""""

core/src/fxcrt/fx_basic_wstring.cpp

Index: core/src/fxcrt/fx_basic_wstring.cpp
diff --git a/core/src/fxcrt/fx_basic_wstring.cpp b/core/src/fxcrt/fx_basic_wstring.cpp
index c097e1fc0923fcc3cec68cd7b254fb27029b8f17..cb94d811968c7f98dc24c39ad8e918932e23aef5 100644
--- a/core/src/fxcrt/fx_basic_wstring.cpp
+++ b/core/src/fxcrt/fx_basic_wstring.cpp
@@ -5,8 +5,10 @@
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include <stddef.h>  // For offsetof().
+#include <cctype>
 
 #include "../../include/fxcrt/fx_basic.h"
+#include "../../include/fxcrt/fx_ext.h"
 #include "../../../third_party/base/numerics/safe_math.h"
 
 // static
@@ -765,8 +767,8 @@ void CFX_WideString::FormatV(const FX_WCHAR* lpszFormat, va_list argList) {
     }
     if (nWidth == 0) {
       nWidth = FXSYS_wtoi(lpsz);
-      for (; *lpsz != 0 && (*lpsz) <= '9' && (*lpsz) >= '0'; lpsz++)
-        ;
+      while (std::isdigit(*lpsz))
+        ++lpsz;
     }
     if (nWidth < 0 || nWidth > 128 * 1024) {
       lpszFormat = L"Bad width";
@@ -781,8 +783,8 @@ void CFX_WideString::FormatV(const FX_WCHAR* lpszFormat, va_list argList) {
         lpsz++;
       } else {
         nPrecision = FXSYS_wtoi(lpsz);
-        for (; *lpsz != 0 && (*lpsz) >= '0' && (*lpsz) <= '9'; lpsz++)
-          ;
+        while (std::isdigit(*lpsz))
+          ++lpsz;
       }
     }
     if (nPrecision < 0 || nPrecision > 128 * 1024) {
@@ -968,7 +970,7 @@ FX_FLOAT FX_wtof(const FX_WCHAR* str, int len) {
     if (str[cc] == '.') {
       break;
     }
-    integer = integer * 10 + str[cc] - '0';
+    integer = integer * 10 + FXSYS_toDecimalDigit(str[cc]);
     cc++;
   }
   FX_FLOAT fraction = 0;
@@ -976,7 +978,7 @@ FX_FLOAT FX_wtof(const FX_WCHAR* str, int len) {
     cc++;
     FX_FLOAT scale = 0.1f;
     while (cc < len) {
-      fraction += scale * (str[cc] - '0');
+      fraction += scale * FXSYS_toDecimalDigit(str[cc]);
       scale *= 0.1f;
       cc++;
     }