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

core/src/fxcrt/fx_basic_util.cpp

Index: core/src/fxcrt/fx_basic_util.cpp
diff --git a/core/src/fxcrt/fx_basic_util.cpp b/core/src/fxcrt/fx_basic_util.cpp
index 46a0dec1e538884370b92f7865aa84d1fde13722..de027fea84807699e8c9f1da0323168ffa96f96f 100644
--- a/core/src/fxcrt/fx_basic_util.cpp
+++ b/core/src/fxcrt/fx_basic_util.cpp
@@ -4,13 +4,18 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
+#include <cctype>
+
 #include "../../include/fxcrt/fx_basic.h"
+#include "../../include/fxcrt/fx_ext.h"
+
 #if _FXM_PLATFORM_ != _FXM_PLATFORM_WINDOWS_
 #include <sys/types.h>
 #include <dirent.h>
 #else
 #include <direct.h>
 #endif
+
 CFX_PrivateData::~CFX_PrivateData() {
   ClearAll();
 }
@@ -100,14 +105,16 @@ void FX_atonum(const CFX_ByteStringC& strc, FX_BOOL& bInteger, void* pData) {
       bNegative = TRUE;
       cc++;
     }
-    while (cc < len) {
-      if (str[cc] < '0' || str[cc] > '9') {
+    while (cc < len && std::isdigit(str[cc])) {
+      // TODO(dsinclair): Are these two checks for overflow needed?
+      if (integer > std::numeric_limits<int>::max() / 10)
         break;
-      }
-      integer = integer * 10 + str[cc] - '0';
-      if (integer < 0) {
+      integer *= 10;
+
+      if (integer > std::numeric_limits<int>::max() - 9)

[Tom Sepez, 2015/11/04 20:33:11]

Sorry, I blew it.  We should be able to parse 4294967295, but now we cant
because at the last character "5", integer is  4294967290 following the
multiplication, and its always larger than 4294967295 - 9.  What we meant to do
is call toDD() earlier

   int digit = FXSYS_toDecimalDigit(str[cc])
then
   if (integer > std::numeric_limits<int>::max() - digit)

[dsinclair, 2015/11/04 21:31:28]

Actually, this code is just broken. If we did overflow, we'd break, and then
take the overflowed value anyway (possibly flipping the sign). All it does when
it overflows is to stop adding new values. It isn't actually handled in any way.

Not sure what the correct result is here, need to check the callers to see what
is done with pData.

[dsinclair, 2015/11/10 00:47:03]

I put it back to the wrong way as that was what the code did before. I left a
todo that it needs to be fixed. This whole function needs to determine what the
right thing to do with overflow is instead of just using the value that
overflowed.

         break;
-      }
+      integer += FXSYS_toDecimalDigit(str[cc]);
+
       cc++;
     }
     if (bNegative) {
@@ -144,7 +151,7 @@ FX_FLOAT FX_atof(const CFX_ByteStringC& strc) {
     if (str[cc] == '.') {
       break;
     }
-    value = value * 10 + str[cc] - '0';
+    value = value * 10 + FXSYS_toDecimalDigit(str[cc]);
     cc++;
   }
   static const FX_FLOAT fraction_scales[] = {
@@ -155,7 +162,7 @@ FX_FLOAT FX_atof(const CFX_ByteStringC& strc) {
   if (cc < len && str[cc] == '.') {
     cc++;
     while (cc < len) {
-      value += fraction_scales[scale] * (str[cc] - '0');
+      value += fraction_scales[scale] * FXSYS_toDecimalDigit(str[cc]);
       scale++;
       if (scale == sizeof fraction_scales / sizeof(FX_FLOAT)) {
         break;