Fix a bug when assign the generation number of indirect objects

core/src/fxcrt/fx_basic_gcc.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../include/fxcrt/fx_ext.h"
 template <class T, class STR_T>
 T FXSYS_StrToInt(STR_T str)
 {
     FX_BOOL neg = FALSE;
     if (str == NULL) {
         return 0;
     }
     if (*str == '-') {
         neg = TRUE;
         str ++;
     }
-    T num = 0;
+    base::CheckedNumeric<T> num = 0;

[Tom Sepez, 2014/09/19 22:35:07]

num doesn't need to be checked.

+    base::CheckedNumeric<T> num_new = num;

[Tom Sepez, 2014/09/19 22:35:07]

maybe this moves to right before line 25, and its called safe_num instead of new
num.

     while (*str) {
         if ((*str) < '0' || (*str) > '9') {
             break;
         }
-        num = num * 10 + (*str) - '0';
+        num_new *= 10;
+        num_new += (*str) - '0';
+        if (!num_new.IsValid()) {
+            break;
+        }
+        num = num_new;

[Tom Sepez, 2014/09/19 22:35:07]

num = new_num.ValueOrDie();

         str ++;
     }
-    return neg ? -num : num;
+    return neg ? -num.ValueOrDie() : num.ValueOrDie();
 }
 template <typename T, typename STR_T>
 STR_T FXSYS_IntToStr(T value, STR_T string, int radix)
 {
     int i = 0;
     if (value < 0) {
         string[i++] = '-';
         value = -value;
     } else if (value == 0) {
         string[0] = '0';
@@ skipping 185 matching lines @@
             buf[wlen] = bstr[i];
         }
         wlen ++;
     }
     return wlen;
 }
 #ifdef __cplusplus
 }
 #endif
 #endif