We only want to read data in case of POLLIN or POLLHUP. Not POLLNVAL or
select error.
We always want to remove the handler, so it doesn't get called in an
infinite loop when error is nval or err.
In zsh source, see main zle event loop in zle_main.c raw_getbyte
function.
For unknown reasons, the pty will occasionally quit running. In these
cases, we still want to remove it so that a fresh one can be created. We
don't actually need this check because error messages from `zle` and
`zpty` are redirected to /dev/null.
One sure way to kill all currently running pty's is to run `exit` in a
subshell. Even without zsh-autosuggestions loaded, the following works:
% zmodload zsh/zpty
% zpty -b foo cat
% zpty -b bar cat
% zpty
(31689) bar: cat
(31666) foo: cat
% $(exit)
% zpty
(finished) bar: cat
(finished) foo: cat
This fixes a small issue in src/widgets.zsh which makes it so if you
alias [ to g[ (as is done in prezto if the gnu-utility module is loaded)
autosuggestions would fail.
The documentation for GNU test mentions that -o and -a should be avoided
if possible because it's not very clear. Also, with zsh and [[ -o
actually tests if an option is set, which makes this option even more
confusing.
