This fixes an edge case for completing shellwords. With a file
"a b.txt" in the current directory, the sequence `:open a\<tab>`
will result in the prompt containing `:open aa\ b.txt`. This is
because the length of the input which is trimmed when replacing with
completion is calculated on the part of the input which is parsed by
shellwords and then escaped (in a separate operation), which is lossy.
In this case it loses the trailing backslash.
The fix provided here refactors shellwords to track both the _words_
(shellwords with quotes and escapes resolved) and the _parts_ (chunks
of the input which turned into each word, with separating whitespace
removed). When calculating how much of the input to delete when
replacing with the completion item, we now use the length of the last
part.
This also allows us to eliminate the duplicate work done in the
`ends_with_whitespace` check.
This changes the completion items to be rendered with shellword
escaping, so a file `a b.txt` is rendered as `a\ b.txt` which matches
how it should be inputted.
8584b38cfb switched to shellwords for
completion in command-mode. This changes the conditions for choosing
whether to complete the command or use the command's completer.
This change processes the input as shellwords up-front and uses
shellword logic about whitespace to determine whether the command
or argument should be completed.
* Fix shellwords delimiter handling
This allows commands such as `:set statusline.center ["file-type"]` to
work. Before the quotes within the list would mess it up.
Also added a test to ensure correct behavior
* Rename Delimiter -> OnWhitespace