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From: Bart Schaefer <schaefer@brasslantern.com>
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Date: Thu, 24 Oct 2013 09:39:29 -0700
In-reply-to: <20131024164829.55842279@pwslap01u.europe.root.pri>
Comments: In reply to Peter Stephenson <p.stephenson@samsung.com>
 "Re: Strange function/pipestatus behavior, maybe a scope bug?" (Oct 24,
 4:48pm)
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Subject: Re: Strange function/pipestatus behavior, maybe a scope bug?
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On Oct 24,  4:48pm, Peter Stephenson wrote:
} Subject: Re: Strange function/pipestatus behavior, maybe a scope bug?
}
} I can't see any problem here, which might not be too surprising if it's
} a race, but I don't see how the following fix can be wrong if pipestatus
} is now working: the most complicated case appears to be if it gets
} called multiple times and STAT_CURSH is set, but even there it looks
} like it's idempotent with respect to lastval (assuming the information
} hasn't changed, of course).

Unfortunately (see my patch which crossed in the mail with yours) there
are cases where updating lastval both from update_job() and then again
from print_job() will in fact end up with the wrong lastval.  You have
to run some pipelines both with and without PIPEFAIL set to see this.
 
} I don't know if this potentially makes one of the calls removable.

I *suspect* that the call in update_job() is removable, but I got
inconsistent results from testing it both ways (hence my conclusion
that there's still a signal handling race).