Re: [PATCH 4/4] completion: avoid user confusion in non-cone mode

> >> Hmph, would an obvious alternative to (1) check against the HEAD (or
> >> the index) to see if the prefix string matches an entity at the
> >> current directory level, and then (2) to prefix the result of the
> >> previous step with "/$(git rev-parse --show-prefix)" work?  That is
> >> something like this:
> >>
> >>     $ cd t
> >>     $ git sparse-checkout add help<TAB>
> >>     ->
> >>     $ git sparse-checkout add /t/helper/
> >
> > I thought bash-completion was only for completions, not for startings
> > as well.  Was I mistaken?
>
> To my mind, the completion is what I as an end user get when I type
> <TAB> to help me formulate input that is acceptable by the command.
> As I said, I consider it a bug (or UI mistake) in the a command if
> it pretends to work inside a subdirecctory but complains when it is
> given a path relative to the current directory, so I'd rather prefer
> the approach to "fix" the underlying command, but if that is too
> much work or cannot be done for whatever reason, the second best
> would be to turn whatever we can do to help the end-user input into
> a form that is accepted by the command without changing what the
> input means.  If it takes more than "appending at the end", that is
> fine, at least by me as an end user.
>
> If you are saying "completion code can only append at the end
> because we can only return strings to be appended, not the entire
> strings, to the readline machinery, so mucking with the start of the
> string is not doable", then sorry---I accept that what we cannot do
> cannot be done, and in that case you are "not mistaken".

> But from the existing use of COMPREPLY[], it didn't look that way
> (it seems __gitcomp is equipped to take fixed prefix to all
> candidates by passing it in $2 and used to complete names of
> configuration variables in a section, but it seems to me that it can
> be repurposed when prefixing "$(git rev-parse --show-prefix)" to a
> given pathname relative to the $cwd).