Re: stdint and cygwin bug

[Eric Blake]

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According to Paul Eggert on 4/5/2007 10:07 AM:
>> -  int check_WINT: WINT_MIN <= 0 && 0 < WINT_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?

On cygwin, wint_t is unsigned, but WINT_MIN was INT_MIN.  Comparing
WINT_MIN to a signed 0 succeeded (using signed comparison), but comparing
it to (wint_t)0 correctly detected that WINT_MIN was not 0 (because it
forced an unsigned compare).  It shows two bugs - first, that WINT_MIN was
not 0; and second, that WINT_MIN was a signed value even though wint_t is not.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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