@@ -48,7 +48,18 @@
#include <sys/types.h>
#include <string.h>
#include <stdio.h>
+#ifdef HAVE_LIMITS_H
+#include <limits.h>
+#endif
+#ifndef UINT_MAX
+#define UINT_MAX ((unsigned int)(~0U)) /* 0xFFFFFFFF */
+#endif
+
+#ifndef INT_MAX
+#define INT_MAX ((int)(UINT_MAX >> 1)) /* 0x7FFFFFFF */
+#endif
+
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#else
@@ -494,28 +505,25 @@
while (ISDIGIT ((unsigned char)**type))
{
+ /* Check whether we can add another digit without overflow. */
+ if (count > INT_MAX / 10)
+ goto overflow;
+
count *= 10;
- /* Check for overflow.
- We assume that count is represented using two's-complement;
- no power of two is divisible by ten, so if an overflow occurs
- when multiplying by ten, the result will not be a multiple of
- ten. */
- if ((count % 10) != 0)
- {
- while (ISDIGIT ((unsigned char) **type))
- (*type)++;
- return -1;
- }
+ if (count > INT_MAX - (**type - '0'))
+ goto overflow;
count += **type - '0';
(*type)++;
}
- if (count < 0)
- count = -1;
+ return count;
- return (count);
+ overflow:
+ while (ISDIGIT ((unsigned char) **type))
+ (*type)++;
+ return -1;
}