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Re: [ANNOUNCEMENT] Updated: Cygwin 2.2.0-1


On Aug  4 20:53, Achim Gratz wrote:
> Warren Young writes:
> > Hereâs an interesting experiment to try on your non-Cygwin POSIX boxes:
> >
> >     $ HOME=/dfjkshkds bash -l
> >     $ echo $HOME
> >
> > Guess what it prints.
> >
> > Hint: It isnât the second-to-last field in /etc/passwd. :)

This is correct behaviour, of course.

> > Spoiler: Apparently Cygwin is already doing the standard thing.

No, it's not.  Or, to phrase it a bit differently, it doesn't perform
thr action it was supposed to do.  My testing seemed to be a teeny bit
half-hearted...

The problem the fix was *supposed* to fix (but it didn't) was to disallow
incoming $HOME values which are non-POSIX or non-absolute paths.  These
$HOME values should be disregarded.

So the idea was:

  set HOME=foo		<- ignored, set HOME from passwd DB entry
  set HOME=C:/foo	<- same
  set HOME=//foo/bar	<- same
  set HOME=/foo/bar	<- valid, taken

Right now, when started from a non-Cygwin process, Cygwin takes the
value of $HOME and simply calls the Win32->POSIX conversion function.
It does so for a long time, but is that right?  Especially if %HOME% is
a non-absolute == relative path, the resulting POSIX value of $HOME
depends on the current directory when starting Cygwin.

This sounds like a terrible idea to me.  Together with cases like
https://cygwin.com/ml/cygwin/2015-07/msg00344.html, and the fact that
$HOME has no meaning in native Windows (HOMEPATH/HOMEDRIVE instead) I'm
inclined to think that any incoming $HOME should make sense from a POSIX
POV, otherwise we take the value from the passwd DB as defined by
/etc/nsswitch.conf.

Does anybody have a *good* reason *not* to change this?

> That's why I offered to ignore the issue.  That also needs nothing to be
> done by me, which is an added benefit.  :-)

That may be the way to go as soon as Cygwin is doing the right thing :}


Corinna

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

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