On Sun, Nov 6, 2022 at 7:50 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
> More questionable are the looping constructs.  I can't come up with a
> way to have the loop end in an error state without the whole shell
> ERREXITing before reaching the end of the loop body.

Found the way (and it should have been obvious):

repeat 1; do false && true; done

The statement `false && true` doesn't itself cause an exit, but does
become $? of the loop.

Now the weird bit is that the attached patch DOES NOT cause a slew of
test failures in C03traps.  E.g. if I run this test standalone:

Src/zsh -f =(<<<"(setopt err_exit
  if true; then
    false
  fi
  print OK
  )")

I get no output and $? = 1.  The exact same code in C03traps.ztst
prints OK, which it should not.  The only difference I can see is that
ZTST_execchunk fiddles with localloops, but I've tried doing that too.

There is the question of why ignoring a false status at the end of a
complex command has so far been considered correct for ERR_EXIT,
according to C03.  This is a disagreement with e.g. bash.