bug#5995: [PATCH] Fix exit status of signal handlers in shell scripts

[Dmitry V. Levin]

On Sat, Jan 30, 2010 at 11:52:31PM +0300, Dmitry V. Levin wrote:
> On Sat, Jan 30, 2010 at 12:28:50PM -0700, Eric Blake wrote:
> > According to Dmitry V. Levin on 1/30/2010 12:18 PM:
> > > The value of `$?' on entrance to signal handlers in shell scripts
> > > cannot be relied upon, so set the exit code explicitly to
> > > 128 + SIGTERM == 143.
> > > * src/Makefile.am (sc_tight_scope): Use `exit 143' in signal handler.
> > 
> > I'm not sure I like the direction this is headed in.  Exiting with 143
> > when a trap is known to be caused by SIGTERM might be okay, but it would
> > be even better to reraise the signal and make the shell also exit by
> > SIGTERM (in case the caller can distinguish between exit by signal and
> > normal exit by status > 128).  But blindly giving status 143 for other
> > signals, like SIGHUP, is just wrong.  If you are going to munge trap
> > handlers to account for races, then you need one trap handler per signal
> > with an appropriate exit status for each.
> 
> One trap handler per signal is overkill in most cases.
> I think that any non-zero exit status would be sufficient.

I just want to remind you that the undefined behaviour still hasn't been
fixed.  Please make a decision what kind of fix seems to be more suitable.


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