unclear documentation of git fetch --tags option and tagopt config

unclear documentation of git fetch --tags option and tagopt config

[乙酸鋰]

Hi,

With git fetch --tags
or remote.origin.tagopt = --tags
git fetch only fetches tags, but not branches.
Current documentation does not mention that no branches are fetched /
pulled when --tags option or remote.origin.tagopt = --tags is
specified.

Regards,
ch3cooli

Re: unclear documentation of git fetch --tags option and tagopt config

[Junio C Hamano]

乙酸鋰 <ch3cooli@gmail.com> writes:

> With git fetch --tags
> or remote.origin.tagopt = --tags
> git fetch only fetches tags, but not branches.
> Current documentation does not mention that no branches are fetched /
> pulled when --tags option or remote.origin.tagopt = --tags is
> specified.

In the canonical form you spell out what you want to fetch from
where, and a lazy "git fetch" or "git fetch origin" that does not
specify what are to be fetched are the special cases.  Because they
do not say what to fetch, they would become a no-op, which would not
be very useful, if there is no special casing for them.  Instead,
they use sensible default, taking refspec from the configuration
variable remote.$name.fetch.

Giving refspecs or the "--tags" option from the command line is a
way to explicitly override this default, hence:

    $ git fetch origin HEAD

only fetches the history leading to the commit at HEAD at the
remote, ignoring the configured refspecs.  As "--tags" is a synonym
to "refs/tags/*:refs/tags/*", "git fetch --tags origin" tells us to
ignore refspecs and grab only the tags, i.e.:

    $ git fetch origin "refs/tags/*:refs/tags/*"

which does not grab any branches.

You can of course do:

    $ git fetch --tags origin refs/heads/master:refs/remotes/origin/master

Re: unclear documentation of git fetch --tags option and tagopt config

[Philip Oakley]

From: "Junio C Hamano" <gitster@pobox.com> Sent: Thursday, December 13, 
2012 6:44 PM
> 乙酸鋰 <ch3cooli@gmail.com> writes:
>
>> With git fetch --tags
>> or remote.origin.tagopt = --tags
>> git fetch only fetches tags, but not branches.
>> Current documentation does not mention that no branches are fetched /
>> pulled when --tags option or remote.origin.tagopt = --tags is
>> specified.
>
> In the canonical form you spell out what you want to fetch from
> where, and a lazy "git fetch" or "git fetch origin" that does not
> specify what are to be fetched are the special cases.  Because they
> do not say what to fetch, they would become a no-op, which would not
> be very useful, if there is no special casing for them.  Instead,
> they use sensible default, taking refspec from the configuration
> variable remote.$name.fetch.
>
> Giving refspecs or the "--tags" option from the command line is a
> way to explicitly override this default, hence:
>
>    $ git fetch origin HEAD
>
> only fetches the history leading to the commit at HEAD at the
> remote, ignoring the configured refspecs.  As "--tags" is a synonym
> to "refs/tags/*:refs/tags/*", "git fetch --tags origin" tells us to
> ignore refspecs and grab only the tags, i.e.:
>
>    $ git fetch origin "refs/tags/*:refs/tags/*"
>
> which does not grab any branches.
>
> You can of course do:
>
>    $ git fetch --tags origin 
> refs/heads/master:refs/remotes/origin/master
>
> --

What would be the best way of updating the documentation to clarify the 
point? Given ch3cooli's previous surprise.

Re: unclear documentation of git fetch --tags option and tagopt config

[Junio C Hamano]

"Philip Oakley" <philipoakley@iee.org> writes:

> What would be the best way of updating the documentation to clarify the 
> point? Given ch3cooli's previous surprise.

Oh, thanks for bringing it up.  I was about to start another message
that begins with "Having said all that..." ;-)

I think the entire paragraph should be rewritten.  The first long
sentence explains that you will get tags that point at the branches
and other stuff you follow by default, so there is no need to
explicitly ask for tags most of the time.  While that is true, it is
secondary in describing what "--tags" is about.  It is to grab all
tags and store them locally, and that needs to come at the very
beginning.

And that auto-following behaviour is already described in the
previous entry for -n/--no-tags.  So how about something like this:

	This is a short-hand for giving "refs/tags/*:refs/tags/*"
	refspec from the command line, to ask all tags to be fetched
	and stored locally.

Note that it is deliberate that the above does not mention tagopt
configuration at all.  The variable was primarily meant to be used
with --no-tags, so that with this:

    [remote "origin"] tagopt = --no-tags

you can "git fetch origin" to keep up with the development on
branches without having to fetch tags from there.  Fetching tags and
only tags from a remote is almost always not what you want; in other
words, remote."origin".tagopt set to --tags is a misconfiguration
99% of the time, unless you are only interested in following tagged
release points.