send-break or EOF exit the shell in "vared"

[Stephane Chazelas <stephane@chazelas.org>]

For context, that's still about trying to answer that "how to
add a timeout to `vared`" question at
https://unix.stackexchange.com/questions/565718/zsh-timeout-for-vared-builtin

I was thinking: vared uses zle, zle is fully programmable, that
shouldn't be too difficult. But so far I've not been able to do
it without a subshell and I ran in a few unexpected behaviours.

In:

zsh -c 'vared -c foo; echo $? $foo'

If I press ^G (send-break widget), that exits the shell (with
status 0), not just "vared".

With:

zsh -c '{ vared -c a; } always { TRY_BLOCK_ERROR=0; echo in always; }; echo $? $a'

Upon ^G, the "always" block is run, but that still exits the
shell (with status 2 this time) despite the TRY_BLOCK_ERROR=0

With:

zle-line-init() stty -icanon time 10 min 0 <&2
zle -N zle-line-init
{
  vared -c var
} always {
  TRY_BLOCK_ERROR=0
  print in always
}
echo "$? $var"


That is where a read() on the terminal will return 0 (EOF) if
nothing is entered within a second, the shell exits as well
(with status 1) not just vared, the "always" block is not run.
Same with vared -e.

My other approaches trying to use TMOUT and a SIGALRM trap or a
zle -F handler that invokes send-break or accept-line (or queues
^G/^M with zle -U) haven't been successful either (either exit
the shell or don't exit zle straight away or at all).

-- 
Stephane