Re: bug#8846: coreutils-8.12 on HP-UX 11.31: 3 of 365 tests failed

[Stefano Lattarini]

On Monday 13 June 2011, Stefano Lattarini wrote:
> On Monday 13 June 2011, Stefano Lattarini wrote:
> > Hi Jim.  Probably you're totally going to hate me today, but ...
> > 
> > On Monday 13 June 2011, Jim Meyering wrote:
> > > 
> > > From d987cf87de5e7e597e295914c536bd332c24cc63 Mon Sep 17 00:00:00 2001
> > > From: Jim Meyering <address@hidden>
> > > Date: Mon, 13 Jun 2011 18:54:53 +0200
> > > Subject: [PATCH] init.sh: redirect FD 9 to stderr again, for Solaris 10 
> > > and HP-UX
> > > 
> > > * tests/init.sh (setup_): When $stderr_fileno_ is not 2, redirect it.
> > > Prior to this change, we would redirect before the shell fork-and-exec
> > > performed via automake's TESTS_ENVIRONMENT, but that redirection was
> > > ineffective on Solaris 10 and HP-UX 11.31, due to the fact that those
> > > systems set the CLOEXEC bit on FDs larger than 2.  Thus our redirection
> > > of FD 9 would not survive the fork-and-exec of running each test script.
> > > ---
> > >  tests/init.sh |    5 +++++
> > >  1 files changed, 5 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/tests/init.sh b/tests/init.sh
> > > index 60d1bc1..d101643 100644
> > > --- a/tests/init.sh
> > > +++ b/tests/init.sh
> > > @@ -317,6 +317,11 @@ path_prepend_ ()
> > > 
> > >  setup_ ()
> > >  {
> > > +  # If we're redirecting a file descriptor larger than 2, say via 
> > > automake's
> > > +  # TESTS_ENVIRONMENT, that redirected FD is closed-on-exec on some 
> > > systems
> > > +  # (at least Solaris 10 and HP-UX 11.x), so redirect it here again.
> > > +  test $stderr_fileno_ = 2 || eval "exec $stderr_fileno_>&2"
> > > +
> > >
> > ... isn't this equivalent to just using ">&2" unconditionally in 'warn_()'?
> > 
> > IMHO, the right fix is to to modify the code in TESTS_ENVIRONMENT to avoid 
> > the
> > definition of $stderr_fileno_ the shell performs closed-on-exec; e.g.,
> > 
> >   TESTS_ENVIRONMENT = ...; \
> >     if test x"`(exec 9>&1 && sh -c 'echo foo >&9' >/dev/null 2>&1)`" = 
> > x'foo'; then
> >        stderr_fileno_=9; export stderr_fileno_;
> >     else
> >        unset stderr_fileno_ || :
> >     fi
> > 
> > If we know that bash and zsh are well behaved, we can even avoid a couple of
> > forks (Cygwin users won't hate us too much then):
> > 
> >  TESTS_ENVIRONMENT = ...; \
> >     if test -n "$${ZSH_VERSION}$${BASH_VERSION}" || \
> >        test x"`(exec 9>&1 && sh -c 'echo foo >&9' >/dev/null 2>&1)`" = 
> > x'foo'
> >     then
> >        stderr_fileno_=9; export stderr_fileno_;
> >     else
> >        unset stderr_fileno_ || :
> >     fi
> > 
> > A better fix would be to do the redirect $stderr_fileno_>&2 in tests/init.sh
> > iff $stderr_fileno_ is closed, but how can that be portably determined
> > without printing trash on the user screen (and for *each* test)?
> >
> But this last observaton makes me think.  The only purpose of $stderr_fileno_
> is to allow the test to print diagnostic on the user's tty, instead of burying
> it in the test logs; at this point, we might do the redirection only if the
> fd 2 is a tty, so that we will know that, in `tests/init.sh', either:
>  [1] $stderr_fileno_ refers to a tty, even after the automake parallel-tests
>      driver has made its own redirections; or:
>  [2] $stderr_fileno_ is simply the file descriptor 2, which is expected to be
>      open for writing in any remotely sane setup.
> Then we can test, from within tests/init.sh, whether $stderr_fileno_ has been
> closed or not by doing:
>   test 2 -eq "$stderr_fileno_" || test -t "$stderr_fileno_"
> and if this is not the case, we eval "exec $stderr_fileno_ >&2" and live
> happily.  All without extra forks or overly complex `TESTS_ENVIRONMENT'
> definitions.
>
Only that BSD make and Solaris dmake, when running in concurrent mode,
redirect stdout/stderr to temporary files or to named or anonymous pipes
(for output serialization); so that my proposed idiom wouldn't work with
them.  Sigh.

Regards,
  Stefano