Re: stdint and cygwin bug

[Paul Eggert]

Eric Blake <address@hidden> writes:

> -  int check_PTRDIFF: PTRDIFF_MIN < 0 && 0 < PTRDIFF_MAX ? 1 : -1;
> -  int check_SIG_ATOMIC: SIG_ATOMIC_MIN <= 0 && 0 < SIG_ATOMIC_MAX ? 1 : -1;
> -  int check_SIZE: 0 < SIZE_MAX ? 1 : -1;
> -  int check_WCHAR: WCHAR_MIN <= 0 && 0 < WCHAR_MAX ? 1 : -1;
> -  int check_WINT: WINT_MIN <= 0 && 0 < WINT_MAX ? 1 : -1;
> +  int check_PTRDIFF: PTRDIFF_MIN < (ptrdiff_t) 0 && (ptrdiff_t) 0 < 
> PTRDIFF_MAX ? 1 : -1;
> +  int check_SIG_ATOMIC: SIG_ATOMIC_MIN <= (sig_atomic_t) 0 && (sig_atomic_t) 
> 0 < SIG_ATOMIC_MAX ? 1 : -1;
> +  int check_SIZE: (size_t) 0 < SIZE_MAX ? 1 : -1;
> +  int check_WCHAR: WCHAR_MIN <= (wchar_t) 0 && (wchar_t) 0 < WCHAR_MAX ? 1 : 
> -1;
> +  int check_WINT: WINT_MIN <= (wint_t) 0 && (wint_t) 0 < WINT_MAX ? 1 : -1;

This fix looks suspicious to me, as I think it might cause the test to
improperly succeed where it used to fail, on hosts with bugs other
than Cygwin.

What exactly is the Cygwin bug?  Why does this change detect it?