Re: Bash tab completion for _git_fetch alias is broken on Git 1.7.7.1

From: Scott Bronson <bronson@rinspin.com>
Date: Nov 12, 2011, 08:08 UTC
Message-ID: <CAKmUPx6TpbLL2GZq6G1nWPPBe=_SsqJmqXs1o9x5BxqR8y9h2Q@mail.gmail.com>
In-Reply-To: <20111110151412.GA11479@goldbirke>

2011/11/10 SZEDER Gábor <szeder@ira.uka.de>

Show 12 quoted lines

> > On Thu, Nov 10, 2011 at 3:09 PM, Johannes Sixt <j.sixt@viscovery.net> wrote:
> > > Am 11/10/2011 4:21, schrieb Junio C Hamano:
> > > > Nathan Broadbent <nathan.f77@gmail.com> writes:
> > > >> Dear git mailing list,
> > > >> I'm assigning the `_git_fetch` bash tab completion to the alias `gf`,
> > > >> with the following command:
> > > >>     complete -o default -o nospace -F _git_fetch gf
> > > >> The tab completion then works fine in git 1.7.0.4, but breaks on git
> > > >> 1.7.7.1, with the following error:
>
> I didn't actually tried, but I guess this is a side-effect of da4902a7
> (completion: remove unnecessary _get_comp_words_by_ref() invocations,

I looked into it and this is exactly right.

Show 23 quoted lines

> Alternatively, you could easily create your own wrapper function
> around _git_fetch(), like this:
>
> _gf () {
>        local cur prev words cword
>        _get_comp_words_by_ref -n =: cur prev words cword
>        _git_fetch
> }
>
>
> However.
>
> Having said all that, I'd like to point out that even if _git_fetch()
> didn't error out when called for the 'gf' alias, it still wouldn't
> work properly.  After 'gf origin <TAB>' it offers the list of remotes
> again and it never offers refspecs, because it calls
> __git_complete_remote_or_refspec(), which
>
>  - depends on the fact that there must be at least two words ('git'
>   and 'fetch') on the command line before the remote, and
>
>  - needs to know the git command (i.e. fetch, pull, or push) to offer
>   the proper refspecs, but it can't find that out from your alias.

Very true. But if you tweak the completion variables, you can fool _git_fetch into working perfectly:

  _gf () {
      COMP_LINE="git fetch${COMP_LINE#gf}"
      let COMP_POINT+=7  # strlen('git fetch') - strlen('gf')
      COMP_WORDS=(git fetch "${COMP_WORDS[@]:1}")
      let COMP_CWORD+=1

      local cur words cword prev
      _get_comp_words_by_ref -n =: cur words cword prev
      _git_fetch
  }

Can anyone find a place where this would fail?

It would be pretty easy to write similar wrappers for _git_add, _git_branch, and all the rest. [*]

Is there any possibility for a full set of wrappers (with better
names) to be merged into the git completions?  A number of
peopl are disappointed that abbreviation completion doesn't
work anymore, myself included:
  https://github.com/bobthecow/git-flow-completion/issues/2
  https://github.com/ndbroadbent/scm_breeze/issues/11

I'm happy to write them if there's a chance they'd be merged. Thank you for all the work you've done on the completions Gábor!

    - Scott

* If I had more time, I'd be tempted to write a function that
would define all the wrapper functions.

    define_wrapper add, ga
    define_wrapper branch, gb
    define_wrapper fetch, gf
    ...

Nothing a little eval metaprogramming can't solve.  :)