hIsTerminalDevice returns True for /dev/null (aka NUL) on Windows

[igloo]

test 2228 is failing for me in an msys window on Windows:

-BlockBuffering Nothing
+LineBuffering
 BlockBuffering Nothing

because isatty behaves unexpectedly on mingw:

#include <stdio.h>
#include <unistd.h>

int main(void) {
    int i;
    i = fileno(stdin);
    printf("%d\n", i);
    i = fileno(stdout);
    printf("%d\n", i);
    i = isatty(0);
    printf("%d\n", i);
    i = isatty(1);
    printf("%d\n", i);
    return 0;
}

$ ./w            
0
1
0
0

$ ./w < /dev/null
0
1
64
0

[simonmar]

isatty does indeed return non-zero for NUL on Windows. In fact, GetFileType also returns FILE_TYPE_CHAR for NUL, so it seems hard to tell them apart.

I'm not planning to do anything about this except for marking the bug as an expected failure, it's a fairly rare corner-case.

[batterseapower]

This test is an unexpected pass for me on Windows. Maybe the difference is that I'm running the test within a Cygwin session (with mintty).