Re: set -e ignored in subshell if part of command list

[Andrew Church]

>"The -e setting shall be ignored when executing the compound list following
>the while, until, if, or elif reserved word, a pipeline beginning with the
>! reserved word, or any command of an AND-OR list other than the last."
>
>(from 
>https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_25_03)
>
>The subshell inherits this state (being part of an and-or list) from its
>parent.

Is that really the intent of the requirement, though?  The same section
states: "This requirement applies to the shell environment and each
subshell environment separately", which I read to mean that the rules
should be evaluated without consideration of any parent or subshell
environment other than the one in which the -e option is being applied.
And the example:

set -e; (false; echo one) | cat; echo two

shows rule 1 ("The failure of any individual command in a multi-command
pipeline shall not cause the shell to exit") not being applied within
the subshell, even though the subshell as a whole is an "individual
command in a multi-command pipeline".  I don't see any suggestion that
the case of an AND-OR list in rule 2 should be treated differently, and
absent an explicit requirement one way or the other, I think the
expected behavior here would be that the behavior of the subshell is
independent of the subshell's context in the parent shell.

  --Andrew Church
    http://achurch.org/