Re: PATCH: test for trap EXIT fix.

[Peter Stephenson <pws@csr.com>]

Bart Schaefer wrote:
> On Oct 2,  3:39pm, Peter Stephenson wrote:
> } We may be able to do some special tricks with `exiting' at the end of
> } execlist(), making sure we don't exit too early from lower down in that
> } case (because of the optimization for a final command to be exec'd if
> } there's nothing left to do).  Then we just execute any top level EXIT trap
> } which has been left to us.
> 
> I'm having a hard time grokking "top level EXIT trap" in that context,
> but I think you must be thinking the right thing, because I can't find
> any other interpretation that makes sense.

`Top level' means whatever's on the front of the list of EXIT traps.  It's
about the only thing we've got we could possibly execute as a trap.  If I'm
following my own logic properly, this means

fn() {
  function TRAPEXIT { echo foo; }
  ( true )
  ( exit )
}

would execute the trap when the subshells exit (as well as when the
function exits), because the function-type trap is not deleted at the start
of the subshell, and is what we have waiting in the queue on the next exit
from anything.  This would match the behaviour the code were executed
outside the function.

The 4.0 behaviour is that only the explicit exit produces a trap; falling
off the end of the subshell in `( true )' doesn't.  I would guess this is
wrong and they should be equivalent.  That may require more special
handling.

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 392070


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