RE: [PATCH v2 4/6] Force test suite traps to be cleared for NonStop ksh

> On January 19, 2018 4:27 PM, Jeff King wrote:
> > On Fri, Jan 19, 2018 at 12:34:04PM -0500, randall.s.becker@rogers.com
> wrote:
> >
> > > From: "Randall S. Becker" <rsbecker@nexbridge.com>
> > >
> > > * t/lib-git-daemon.sh: fix incompatibilities with ksh traps not being
> > >   cleared automatically on platform. This caused tests to seem to fail
> > >   while actually succeeding.
> > >
> > > Signed-off-by: Randall S. Becker <rsbecker@nexbridge.com>
> > > ---
> > >  t/lib-git-daemon.sh | 3 +++
> > >  1 file changed, 3 insertions(+)
> > >
> > > diff --git a/t/lib-git-daemon.sh b/t/lib-git-daemon.sh index
> > > 987d40680..955beecd9 100644
> > > --- a/t/lib-git-daemon.sh
> > > +++ b/t/lib-git-daemon.sh
> > > @@ -68,6 +68,7 @@ start_git_daemon() {
> > >  		test_skip_or_die $GIT_TEST_GIT_DAEMON \
> > >  			"git daemon failed to start"
> > >  	fi
> > > +	trap '' EXIT
> > >  }
> >
> > I don't think this can be right. The way these traps are supposed to work is:
> >
> >   - as soon as test-lib.sh is loaded, we "trap die EXIT" to catch an
> >     accidental death/exit from one of the scripts
> >
> >   - when test_done is called, we clear the trap (i.e., it is OK to exit
> >     now because the script has given us a positive indication that all
> >     tests have been run)
> >
> >   - while the child git-daemon is running, we'd want to clean up after
> >     ourselves. So during start_git_daemon() we add our cleanup (followed
> >     by the original "die", because shell traps don't push onto a stack).
> >     And then at stop_git_daemon(), we restore the original die trap.
> >
> > But this patch means that while git-daemon is running, we have no trap at
> all!
> > That means that a failed test which causes us to exit would leave a
> > child daemon running.
> >
> > Furthermore, both of these functions now drop the 'die' trap entirely,
> > meaning the script would fail to notice premature exit from one of the
> > test snippets.
> >
> > So while this may be papering over a problem on NonStop, I think it's
> > breaking the intent of the traps.
> >
> > I'm not sure what the root of the problem is, but it sounds like ksh
> > may be triggering EXIT traps when we don't expect (during function
> returns?
> > Subshell exits? Other?)
> 
> The "unexpected" EXIT traps are exactly the issue we found when working
> with the platform support team. There was some discussion about what the
> right expectation was, and I was not able to have a change made to ksh on
> the platform. The problem may have a similar (identical?) root cause to the
> Perl exit issues we are also experiencing that is in their hands. I'm currently
> retesting without this change (results in 36 hours ☹ ). Is there a preferred
> way you would like me to bypass this except on NonStop? I can add a check
> based on uname.