bug#10257: 23.3.1 Cygwin: network drives - file is write protected (false positive)

[Eli Zaretskii]

> Date: Wed, 14 Dec 2011 09:29:47 -0500
> From: Ken Brown <kbrown@cornell.edu>
> CC: Eli Zaretskii <eliz@gnu.org>, 10257@debbugs.gnu.org
> 
> So can you look into how the native Windows port implements 
> check_writable?

It calls `access', whose implementation is in w32.c:sys_access.  It
mostly calls GetFileAttributes and that's it.  If you want to check NT
security ACLs on Cygwin, then what the native build does will not be
good enough for you.  But you can perhaps fall back on that if the UID
and GID are bogus (see my other mail).