bug#56712: 29.0.50; x-dnd-tests-do-direct-save fails on Cygwin

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> Yes, thus my "if this test should ever run" condition.
>
> IOW, the code produces 3 slashes by concatenating 2 strings, but the
> results are only correct on Posix filesystems.  So at least a comment
> is in order there, because how long would it take, you think, for
> someone to copy/paste that code into an entirely different context?

I see, I'll add a comment there.