Fix a bug when assign the generation number of indirect objects

core/src/fxcrt/fx_basic_gcc.cpp

Index: core/src/fxcrt/fx_basic_gcc.cpp
diff --git a/core/src/fxcrt/fx_basic_gcc.cpp b/core/src/fxcrt/fx_basic_gcc.cpp
index 7f5bbade66c38d188171c9b9b701e2dbc969eb98..93c71ce66028fd4e6b25cc73f55f529df91727b2 100644
--- a/core/src/fxcrt/fx_basic_gcc.cpp
+++ b/core/src/fxcrt/fx_basic_gcc.cpp
@@ -4,6 +4,7 @@
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
+#include <limits>
 #include "../../include/fxcrt/fx_ext.h"
 template <class T, class STR_T>
 T FXSYS_StrToInt(STR_T str)
@@ -21,6 +22,9 @@ T FXSYS_StrToInt(STR_T str)
         if ((*str) < '0' || (*str) > '9') {
             break;
         }
+        if (num > (std::numeric_limits<T>::max() - 9) / 10) {
+            break;
+        }
         num = num * 10 + (*str) - '0';
         str ++;
     }