www/nginx pkg-plist + pkgng (detectable?)

[Michael Gmelin]

On Wed, 10 Apr 2013 09:02:29 +0100
Chris Rees <utisoft at gmail.com> wrote:

> On 10 April 2013 07:13, Baptiste Daroussin <bapt at freebsd.org> wrote:
> > On Tue, Apr 09, 2013 at 08:59:50PM +0200, Michael Gmelin wrote:
> >> On Tue, 9 Apr 2013 19:43:15 +0100
> >> Chris Rees <utisoft at gmail.com> wrote:
> >>
> >>
> >> >
> >> > No, it's a bug in pkgng; it should respect @cwd.
> >> >
> >
> > No it is not.
> >
> > While i agree with pkgng that should repect @cwd (it surely does)
> >
> > There is nothing written anywhere that will waranty you that the
> > @exec line will be parsed in order ro prepend @cwd path to a path
> > you provide. the only thing doing that is %D.
> >
> > A user MUST add %D and have complete path in @exec lines
> >
> > In fact in that case it works by chance becauce of how pkg_install
> > treat plist.
> 
> Am I misunderstanding the meaning of "current working directory"?
> 
> When mkdir is called, it should create the directory in @cwd.
> pkg_install's behaviour is correct here, and pkgng's is not.
> 
> Chris

pkg_create(1) says:

@cwd [directory]
             Set the internal directory pointer to point to directory.
             All subsequent *filenames* will be assumed relative to this
             directory. If no directory argument is given, it will set
             the internal directory pointer to the first prefix value.
             Note: @cd is also an alias for this command.

but as far as the package manager is concerned, www/nginx-dist is an
argument to mkdir in the exec call (@exec mkdir -p -m 755
www/nginx-dist) and not a filename.

Also the porters handbook uses %D in all its examples, but offers no
explicit explanation.

That said, the way pkg_add is implemented, it changes to directories as
a side effect of using its PUSHOUT macro in
usr.sbin/pkg_install/add/extract.c (I only glanced at that, but that
seems to be the reason why this is happening). So commands get executed
within `pwd` == @cwd.

So there is definitely a backwards compatibility problem for the sheer
reason of that "it worked before". I don't thing pkg should adopt this
behavior (it seems like a bad idea long term), but it should detect it
somehow. A simple approach to detect this could be chdiring
to /var/empty in pkg before executing the call so it will fail in case
the path used within @exec is relative.

Cheers,
Michael

-- 
Michael Gmelin