isspace() behaviour

[Patrick Welche]

Chasing a problem in print/pmw, I came across the following difference
in behaviour:

#include <ctype.h>
#include <stdio.h>

int main()
{
        printf("%d", isspace(0xffffffffu));

        return 0;
}

causes a segmentation fault on NetBSD-current/amd64, but returns 0 on
ubuntu 24. One could say "don't do that, 0xffffffffu isn't a valid char".
(That value was used in the program as "an EOF occured when that char
was read".)

Comments?


Cheers,

Patrick