Try to fix #313 again

include/rapidjson/reader.h

@@ -928,7 +928,7 @@ private:
                 if (expMinus) {
                     while (s.Peek() >= '0' && s.Peek() <= '9') {
                         exp = exp * 10 + (s.Take() - '0');
-                        if (exp >= 429496729) {                     // Issue #313: prevent overflow exponent
+                        if (exp >= 214748364) {                         // Issue #313: prevent overflow exponent
                             while (s.Peek() >= '0' && s.Peek() <= '9')  // Consume the rest of exponent
                                 s.Take();
                         }

test/unittest/readertest.cpp

@@ -228,10 +228,11 @@ static void TestParseDouble() {
     TEST_DOUBLE(fullPrecision, "2.2250738585072011e-308", 2.2250738585072011e-308); // http://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/
     TEST_DOUBLE(fullPrecision, "1e-00011111111111", 0.0);                           // Issue #313
     TEST_DOUBLE(fullPrecision, "-1e-00011111111111", -0.0);
-    TEST_DOUBLE(fullPrecision, "1e-429496729", 0.0);                                // Maximum supported negative exponent
+    TEST_DOUBLE(fullPrecision, "1e-214748363", 0.0);                                  // Maximum supported negative exponent
+    TEST_DOUBLE(fullPrecision, "1e-214748364", 0.0);
+    TEST_DOUBLE(fullPrecision, "1e-21474836311", 0.0);
     TEST_DOUBLE(fullPrecision, "0.017976931348623157e+310", 1.7976931348623157e+308); // Max double in another form
 
-
     // Since
     // abs((2^-1022 - 2^-1074) - 2.2250738585072012e-308) = 3.109754131239141401123495768877590405345064751974375599...  10^-324
     // abs((2^-1022) - 2.2250738585072012e-308) = 1.830902327173324040642192159804623318305533274168872044...  10 ^ -324