TEST RELEASE: Cygwin 2.5.0-0.1

Corinna Vinschen corinna-cygwin@cygwin.com
Sun Jan 24 11:57:00 GMT 2016

Hi Cygwin friends and users,

I released a new Cygwin TEST version 2.5.0-0.1.

This release introduces a major change addressing developers only, so
as a user you can skip this test release.

tl;dr: Cygwin 2.5.0 switches Cygwin from the Solaris ACL API to the
       POSIX.1e ACL API.

Since the year 2000, Cygwin supports a POSIXoid ACL emulation.  This
emulation is based on the Solaris API, which is only marginally
comparable to the POSIX ACL API defined in the withdrawn draft

At about the same time SGI started to implement POSIX.1e which
eventually became libacl in 2001.  Libacl is the POSIX ACL
implementation used on Linux.

With Cygwin 2.4.0, Cygwin introduced a major revamp of the POSIX ACL
emulation.  This new emulation is complete in the sense that the ACL
handling covers all of POSIX.1e quirks.  This in turn allows to use
the POSIX.1e API.

The Solaris API is the base implementation and stays available.  The
POSIX.1e API is implemented in terms of the Solaris types and mainly
a slim layer on top of the Solaris API.

Changes for developers:

- The full set of POSIX.1e functions is now available.

- Most of the libacl extensions are available as well.  The only
  exceptions right now are the two functions perm_copy_file and
  perm_copy_fd.  These can be added later.  Somebody just has to do it :)

- The <sys/acl.h> header now *only* exposes the POSIX.1e API.

- To get access to the Solaris API, you will have to include
  <cygwin/acl.h> now.

- There's a new header <acl/libacl.h> which exposes the libacl extension

Please give this new POSIX.1e ACL implementation a test.  If you have
a project or maintain a package utilizing ACLs, please make sure that
your project picks up the new POSIX.1e API and that it works as desired.

Projects like emacs, vim, coreutils come to mind...

Have fun,

(*) http://wt.tuxomania.net/publications/posix.1e/

Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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