Bash tab completion for _git_fetch alias is broken on Git 1.7.7.1

Bash tab completion for _git_fetch alias is broken on Git 1.7.7.1

[Nathan Broadbent]

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:

    -bash: [: 2: unary operator expected


Here is the related issue on github (the project is a set of git shortcuts):
https://github.com/ndbroadbent/scm_breeze/issues/11


Thanks for your time, I'd really appreciate some help!


Regards,
Nathan B

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

[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:

We have been cooking for 1.7.8 and have the first release candidate
1.7.8-rc1; could you try it and report what you find out?

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

[Johannes Sixt]

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:
> 
> We have been cooking for 1.7.8 and have the first release candidate
> 1.7.8-rc1; could you try it and report what you find out?

It looks like _git_fetch is not meant to be called directly. All git
completions must go through _git.

See also this post:

http://thread.gmane.org/gmane.comp.version-control.msysgit/13310/focus=13335

-- Hannes

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

[Nathan Broadbent]

So, this is a feature, not a bug... Tab completion for aliases is
really useful. It's important enough to me that I won't stop until
I've found a solution.
I can appreciate that _git_fetch is not currently meant to be called
directly, but we found a way to utilize it when it previously worked.
Perhaps the scope of these completion functions could be expanded to
allow for aliases? I'll attempt to submit a patch if someone can give
me approval.


Thanks,
Nathan


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:
> >
> > We have been cooking for 1.7.8 and have the first release candidate
> > 1.7.8-rc1; could you try it and report what you find out?
>
> It looks like _git_fetch is not meant to be called directly. All git
> completions must go through _git.
>
> See also this post:
>
> http://thread.gmane.org/gmane.comp.version-control.msysgit/13310/focus=13335
>
> -- Hannes

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

[Nathan Broadbent]

> No change with 1.7.8-rc1, tab completion still fails

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

[SZEDER Gábor]

Hi,

 
[Please don't top-post.]

> 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

I assume you have an

  alias gf="git fetch"

somewhere, right?

> > >> 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,
2011-04-28), which was in v1.7.6.  Since the clean-up in that commit
we only call _get_comp_words_by_ref() in the top-level completion
functions _git() and _gitk() to populate completion-related variables
($cur, $prev, $words, $cword), so invoking any _git_<cmd>() completion
function directly causes an error or wrong behavior, because all those
variables are empty.

Calling a completion function directly was not an issue earlier,
because every _git_<cmd>() completion function invoked
_get_comp_words_by_ref() to populate those variables, or in the
pre-_get_comp_words_by_ref() times they just accessed the
completion-related bash variables $COMP_WORDS and $COMP_CWORD
directly.


On Thu, Nov 10, 2011 at 04:52:33PM +0800, Nathan Broadbent wrote:
> So, this is a feature, not a bug... Tab completion for aliases is
> really useful. It's important enough to me that I won't stop until
> I've found a solution.
> I can appreciate that _git_fetch is not currently meant to be called
> directly, but we found a way to utilize it when it previously worked.
> Perhaps the scope of these completion functions could be expanded to
> allow for aliases? I'll attempt to submit a patch if someone can give
> me approval.

The quickest way would be to just revert da4902a7, but it would be the
dirtiest, too: it would bring back a lot of redundant calls to
_get_comp_words_by_ref() and it might have side-effects under zsh (but
I didn't think this through).

It would be a bit more clever to revert only parts of da4902a7, i.e.
to bring back _get_comp_words_by_ref() calls in _git_<cmd> completion
functions but not in __git_<whatever>() helper functions.  This way
_git_<cmd>() functions would have their completion-related variables
initialized even when called directly instead through _git(), and
_get_comp_words_by_ref() would be called "only" twice during a single
completion.  But that's still one too many, and again: there can be
issues with zsh.

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.


Best,
Gábor

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

[Scott Bronson]

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


> 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.  :)

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

[Scott Bronson]

2011/11/12 Scott Bronson <bronson@rinspin.com>:
> 2011/11/10 SZEDER Gábor <szeder@ira.uka.de>
>> > 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,
>> ...
>> Alternatively, you could easily create your own wrapper function
>> around _git_fetch(), like this:
> Very true.  But if you tweak the completion variables, you can fool
> _git_fetch into working perfectly:
> * If I had more time, I'd be tempted to write a function that
> would define all the wrapper functions.

I couldn't stop thinking about it last night, I had to try it.  Here's the
result, seems to work great:


    __define_git_completion () {
    eval "
        _git_$2_shortcut () {
            COMP_LINE=\"git $2\${COMP_LINE#$1}\"
            let COMP_POINT+=$((4+${#2}-${#1}))
            COMP_WORDS=(git $2 \"\${COMP_WORDS[@]:1}\")
            let COMP_CWORD+=1

            local cur words cword prev
            _get_comp_words_by_ref -n =: cur words cword prev
            _git_$2
        }
    "
    }

    __git_shortcut () {
        type _git_$2_shortcut &>/dev/null || __define_git_completion $1 $2
        alias $1="git $2 $3"
        complete -o default -o nospace -F _git_$2_shortcut $1
    }

    __git_shortcut  ga    add
    __git_shortcut  gb    branch
    __git_shortcut  gba   branch -a
    __git_shortcut  gco   checkout
    __git_shortcut  gci   commit -v
    __git_shortcut  gcia  commit '-a -v'
    __git_shortcut  gd    diff
    __git_shortcut  gdc   diff --cached
    __git_shortcut  gds   diff --stat
    __git_shortcut  gf    fetch
    __git_shortcut  gl    log
    __git_shortcut  glp   log -p
    __git_shortcut  gls   log --stat


On Github:
https://github.com/bronson/dotfiles/blob/731bfd951be68f395247982ba1fb745fbed2455c/.bashrc#L81

It would be nice to see the __define_git_completion function merged
upstram. Possible?

    - Scott

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

[Nathan Broadbent]

2011/11/13 Scott Bronson <bronson@rinspin.com>
>
> 2011/11/12 Scott Bronson <bronson@rinspin.com>:
> > 2011/11/10 SZEDER Gábor <szeder@ira.uka.de>
> >> > 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,
> >> ...
> >> Alternatively, you could easily create your own wrapper function
> >> around _git_fetch(), like this:
> > Very true.  But if you tweak the completion variables, you can fool
> > _git_fetch into working perfectly:
> > * If I had more time, I'd be tempted to write a function that
> > would define all the wrapper functions.
>
> I couldn't stop thinking about it last night, I had to try it.  Here's the
> result, seems to work great:
>
>
>    __define_git_completion () {
>    eval "
>        _git_$2_shortcut () {
>            COMP_LINE=\"git $2\${COMP_LINE#$1}\"
>            let COMP_POINT+=$((4+${#2}-${#1}))
>            COMP_WORDS=(git $2 \"\${COMP_WORDS[@]:1}\")
>            let COMP_CWORD+=1
>
>            local cur words cword prev
>            _get_comp_words_by_ref -n =: cur words cword prev
>            _git_$2
>        }
>    "
>    }
>
>    __git_shortcut () {
>        type _git_$2_shortcut &>/dev/null || __define_git_completion $1 $2
>        alias $1="git $2 $3"
>        complete -o default -o nospace -F _git_$2_shortcut $1
>    }
>
>    __git_shortcut  ga    add
>    __git_shortcut  gb    branch
>    __git_shortcut  gba   branch -a
>    __git_shortcut  gco   checkout
>    __git_shortcut  gci   commit -v
>    __git_shortcut  gcia  commit '-a -v'
>    __git_shortcut  gd    diff
>    __git_shortcut  gdc   diff --cached
>    __git_shortcut  gds   diff --stat
>    __git_shortcut  gf    fetch
>    __git_shortcut  gl    log
>    __git_shortcut  glp   log -p
>    __git_shortcut  gls   log --stat
>
>
> On Github:
> https://github.com/bronson/dotfiles/blob/731bfd951be68f395247982ba1fb745fbed2455c/.bashrc#L81
>
> It would be nice to see the __define_git_completion function merged
> upstram. Possible?
>
>    - Scott


You are amazing!!! Thanks so much for this!


Nathan