- /* Test for overflow, since some calloc implementations don't have
- proper overflow checks. But omit overflow and size-zero tests if
- HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
- returns NULL if successful. */
- if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s))
+ /* Test for overflow, since objects with size greater than
+ PTRDIFF_MAX cause pointer subtraction to go awry. Omit size-zero
+ tests if HAVE_GNU_CALLOC, since GNU calloc never returns NULL if
+ successful. */
+ if (xalloc_oversized (n, s)