Space in interactive menu select

[Thayne <astrothayne@xxxxxxxxx>]

With the following (minimal) .zshrc:

zmodload zsh/complist
zstyle ':completion:*' menu select yes interactive
autoload -Uz compinit
compinit

If I finish the word that is being completed myself, then press space, it
starts completing for the next word, but if I then accept a completion for
that word, it then replaces *both* words that I typed during completion.
https://asciinema.org/a/189304 shows an illustration of this.

This is very unexpected behaviour. I would expect pressing a space during
interactive menu selection to stop the current completion and insert a
space after what has been typed so far. Or at least that is how I would
like it to happen, but as far as I can tell there isn't a way to accomplish
that.

I have tried using `bindkey -M menuselect ' ' self-insert`, but that
doesn't make a difference. `bindkey -M menuselect ' ' accept-line` makes it
so a space is treated the same as enter, which is less surprising, but is a
little annoying if I start the completion, realize that the completion
doesn't have the option I actually need, type the real option, then press
space.

I've also tried creating a custom zle widget that calls `zle send-break`
and then `zle self-insert`. And bind space to that widget, but that doesn't
work either (it looks like it acts the same as `accept-line`.

This seems like a bug to me.

Thayne McCombs