Re: openat, failing fchdir

[Bruce Korb]

On 12/23/10 06:52, Eric Blake wrote:
> Unfortunately, it is not possible to pass fds on cygwin; it is not
> possible to implement SCM_RIGHTS on top of what Windows provides.  Then
> again, cygwin's *at functions don't need replacing, so it's a moot
> point.  The whole exercise here is how to cater to systems that don't
> support native *at correctly.

It is slightly more complicated than that:  The *at gnulib modules
need to not drag in gnulib modules that have an extended interface
requirement.  viz. a call to set_program_name().

As has been pointed out in this thread, there are lots of end-case
issues that need resolution for a perfect implementation.
An "adequate" implementation needs to not seg fault during
an attempt to print an informative message.  That can be handled
by either not necessarily calling error() on an error, or by
changing error() to not require that program_name be set.

When I get back from my Christmas weekend, I propose fiddling the
code the least invasive way possible for libposix and let the
Perfect Implementation come later.  I'd rather to rework than
stall around any more.