Completing paths with spaces on windows about rustyline

[gwenn]

Currently the escape/unescape logic works only on unix.
Maybe we can try to use shell-escape (but the crate does not provide the unescape) !

[klemens]

Yes, using shell-escape seems better than trying to come up with our own logic. However, it always escapes using single quotes on unix, which might not be the desired behaviour (but it certainly is the simplest). Using it only for windows also seems possible, what do you think?

I guess unescape is missing, because it is only ever needed when actually writing a shell. But it shouldn't be too difficult to write a parser for quoted strings for windows. We also need to update extract_word to recognize these partially quoted strings correctly: ls "my pict<TAB>

I will see if I can come up with a pull request implementing this.