push.default???

push.default???

[Paolo Bonzini]

Hi all, I just upgraded to git 1.6.3 and found this new little gem 
called push.default...

Now, having gone through an attempt of proposing a different semantics 
for "git push", this stroke me as total nonsense, because now we have 
two totally incompatible ways to specify push refspecs.

A sensible implementation would have been something like this:

1) Also in 1.6.3, invent a special refspec for "tracking", something 
like "HEAD>" (of course this is not a special case; "refs/heads/*>" 
would also work, yadda yadda)

2) Also in 1.6.3, add a "--push={current,tracking,matching,mirror}" 
option to "git remote add" that would set up a push refspec without the 
need to actually know refspec syntax. (--mirror would become just a 
synonym for --push=mirror).

3) Possibly, in 1.6.3 make "git clone" add a "push = :" line for the 
origin branch.  This was actually suggested in a patch by myself.

4) in 1.6.4 or 1.7.0, make "git push" fail outright if there is no push 
line, with text suggesting

   For remotes that you will create in the future, please use the
   `--push' argument to `git remote add'.  For existing remotes,
   you can use the following command to obtain the same behavior as
   git 1.6.3:

     git config --add remote.origin.push :

   For alternative configurations, please look at the release notes
   for git 1.6.4.

so that it's a quick cut'n'paste into the shell to fix this (though once 
per repository).


I know it's my fault that I did not follow the development of git last 
March, but I could not help ranting that it is extremely wrong to 
specify what to push without a refspec (in the configuration, not in the 
command line -- the cmdlines can always have more "porcelain" attached 
to them).

(1) and (2) in particular can still be straightened, and (4) too maybe. 
  I can work on the implementation if we agree on the details.

Paolo

Re: push.default???

[Junio C Hamano]

Paolo Bonzini <bonzini@gnu.org> writes:

> 1) Also in 1.6.3, invent a special refspec for "tracking", something
> like "HEAD>" (of course this is not a special case; "refs/heads/*>"
> would also work, yadda yadda)

You cannot do anything "in 1.6.3"; The ship has already left the port.

You can set push.default to "tracking" and have it take effect for all
remotes you interact with from your repository (set remote.$name.push for
some remotes you do not want this to take effect).  Instead, you could
leave push.default to "matching" and define remote.$name.push with the
"push tracking" magic you are going to invent for a specific remote.

Both arrangements can do the same thing, so even if your "HEAD>" is never
supported, there is no functionality loss (similarly, if we did not have
"push.default", we would be Ok if we had your "HEAD>" magic).  Depending
on which one you would want to use for majority of remotes you interact
with, you would want both.

So in that sense, I do not think the current situation is such a "total
nonsense" as you seem to be painting it [*1*].  It just does not have the
other half of the story that you are bringing up now.

In other words, I do not have objection to your "HEAD>" at the conceptual
level.  At the syntax level, I suspect people will have suggestions for
better alternatives.

In retrospect, because a push refspec (or "magic" you will be adding) for
a specific remote is called "remote.$name.push", it might have been a
better idea to use "remote.push" instead of "push.default" as the name of
the configuration variable.  Then the rules can become

	* if you ask explicitly from the command line, it wins;
	* otherwise, if you have remote.$name,push, it is used;
        * otherwise, if you have remote.push, it is used;
        * otherwise, the default is "matching".

which is slightly nicer to read, than the current situation where the
third rule talks about push.default instead.

> 2) Also in 1.6.3, add a "--push={current,tracking,matching,mirror}"
> option to "git remote add" that would set up a push refspec without
> the need to actually know refspec syntax. (--mirror would become just
> a synonym for --push=mirror).

This is probably sensible if/when we do (1).  

But here I have to qualify what I mean by (1).  I am not married to the
idea of using remote.$name.push at all.  I view (1) as solving this issue:

        Currently with push.default, we can only set push.default to
        something other than "matching" and have specific remote override
        that with remote.$name.push with a more concrete refspec, if we
        want to have the magic 'tracking push' semantics.

        We want to have a way to say "for this and that particular
        remotes, use the magic tracking push" in a more direct way.

And hiding the detail of how this "direct way" is implemented from the end
user is a good idea.

> 3) Possibly, in 1.6.3 make "git clone" add a "push = :" line for the
> origin branch.  This was actually suggested in a patch by myself.

This contradicts with (1), I think.  The default after cloning is
"matching", and if one wants to change it to "track", one not just needs
to set push.default but also needs to remove/twaek remote.origin.push
if you add such a line.

So I do not think this one makes much sense.

> 4) in 1.6.4 or 1.7.0, make "git push" fail outright if there is no
> push line, with text suggesting

This was already part of one possible option for push.default (change the
built-in default to 'nothing-and-warn') when it was introduced, wasn't it?
Instead of suggesting to configure remote.$name.push, it would suggest to
set push.default to a desired value, which I think is a more sensible
thing to do.

[Footnote]

*1* ... even though I admit that I am not convinced 'push "tracking"'
makes much sense for me to begin with, because pushing a branch to the
branch it forked from rarely if ever makes sense in my workflow.  But I
can see 'push "tracking"' makes sense in some situations and people seem
to want to do this, so we have already added push.default.

Re: push.default???

[Paolo Bonzini]

> You cannot do anything "in 1.6.3"; The ship has already left the port.

Yes, that was me reasoning out loud.

>> 4) in 1.6.4 or 1.7.0, make "git push" fail outright if there is no
>> push line, with text suggesting
> 
> This was already part of one possible option for push.default (change the
> built-in default to 'nothing-and-warn') when it was introduced, wasn't it?
> Instead of suggesting to configure remote.$name.push, it would suggest to
> set push.default to a desired value, which I think is a more sensible
> thing to do.

Yes, that was also reasoning out loud.  It makes sense.

Anyway, suggestion will be helpful for the "tracking" behavior refspec 
syntax.

Thanks for the remarks,

Paolo

Re: push.default???

[Finn Arne Gangstad]

On Mon, Jun 22, 2009 at 12:02:33PM +0200, Paolo Bonzini wrote:
> Hi all, I just upgraded to git 1.6.3 and found this new little gem  
> called push.default...
> [...]

You should have been here when we discussed this! :)

> 1) Also in 1.6.3, invent a special refspec for "tracking", something  
> like "HEAD>" (of course this is not a special case; "refs/heads/*>"  
> would also work, yadda yadda)

Yes, this is a weakness righ now - the only way to get tracking
semantics is to set push.default. I could not find a very good way of
specifying this. We currently have the magic refspecs : and
HEAD. Adding a ">" to "HEAD>" would be annoying I think, since it has
to be quoted in the shell.

Maybe we can use ":" as an escape, it is not allowed in refspecs.
Something like "::tracking" (and we cold also have "::matching",
"::current" and so on for completeness)

> 2) Also in 1.6.3, add a "--push={current,tracking,matching,mirror}"  
> option to "git remote add" that would set up a push refspec without the  
> need to actually know refspec syntax. (--mirror would become just a  
> synonym for --push=mirror).

Sounds like a good idea, the options would also make sense to push I think,
so you can "git push [--current|tracking|...] ".

> 3) Possibly, in 1.6.3 make "git clone" add a "push = :" line for the  
> origin branch.  This was actually suggested in a patch by myself.

This would destroy the intention of my patch, it would render the
configuration variable pointless I think (and would also silently push
matching).

> 4) in 1.6.4 or 1.7.0, make "git push" fail outright if there is no push  
> line, with text suggesting [...]

Hopefully we can get to this stage, that a unconfigured "git push"
gives a small message, indicating how to configure it, and not push
anything. Most "oldtimers" should have configured this already, so it
should not break many setups.

- Finn Arne

Re: push.default???

[Paolo Bonzini]

Finn Arne Gangstad wrote:
> On Mon, Jun 22, 2009 at 12:02:33PM +0200, Paolo Bonzini wrote:
>> Hi all, I just upgraded to git 1.6.3 and found this new little gem  
>> called push.default...
>> [...]
> 
> You should have been here when we discussed this! :)

Yes, mea culpa.  But I would have expected a *lot* more discussion from 
what I remembered about the git list and community. :-)

>> 1) Also in 1.6.3, invent a special refspec for "tracking", something  
>> like "HEAD>" (of course this is not a special case; "refs/heads/*>"  
>> would also work, yadda yadda)
> 
> Yes, this is a weakness righ now - the only way to get tracking
> semantics is to set push.default. I could not find a very good way of
> specifying this. We currently have the magic refspecs : and
> HEAD. Adding a ">" to "HEAD>" would be annoying I think, since it has
> to be quoted in the shell.

Yes, > has the disadvantage of quoting.

> Maybe we can use ":" as an escape, it is not allowed in refspecs.
> Something like "::tracking" (and we cold also have "::matching",
> "::current" and so on for completeness)

But that would lose the possibility to use wildcards.

Before going on, can you explain your use case for --push=tracking (in a 
case where --push=current wouldn't do the same)?

>> 4) in 1.6.4 or 1.7.0, make "git push" fail outright if there is no push  
>> line, with text suggesting [...]
> 
> Hopefully we can get to this stage, that a unconfigured "git push"
> gives a small message, indicating how to configure it, and not push
> anything. Most "oldtimers" should have configured this already, so it
> should not break many setups.

Agreed.  Possibly with a "git remote" command to add a push refspec.

Paolo

Re: push.default???

[Finn Arne Gangstad]

On Tue, Jun 23, 2009 at 02:59:10PM +0200, Paolo Bonzini wrote:
[...]
> Before going on, can you explain your use case for --push=tracking (in a  
> case where --push=current wouldn't do the same)?

The idea with "tracking" is to push the current branch to wherever it
would pull from, making push & pull "equivalent" in some sense.

This is different from "current" if you have/choose to name the local
branch something else than the remote branch. This happens a lot when
using multiple remotes.

E.g. some remotes have only a single active branch called "master",
and you have to name it something else locally, or several people have
local branches called "beta", and you have to name it something like
"fred-beta" locally if you are working on fred's beta.

- Finn Arne

Re: push.default???

[Andreas Ericsson]

Finn Arne Gangstad wrote:
> On Tue, Jun 23, 2009 at 02:59:10PM +0200, Paolo Bonzini wrote:
> [...]
>> Before going on, can you explain your use case for --push=tracking (in a  
>> case where --push=current wouldn't do the same)?
> 
> The idea with "tracking" is to push the current branch to wherever it
> would pull from, making push & pull "equivalent" in some sense.
> 
> This is different from "current" if you have/choose to name the local
> branch something else than the remote branch. This happens a lot when
> using multiple remotes.
> 
> E.g. some remotes have only a single active branch called "master",
> and you have to name it something else locally, or several people have
> local branches called "beta", and you have to name it something like
> "fred-beta" locally if you are working on fred's beta.
> 

Umm. Why not name it after the feature you're working on instead of the
branch you started from? That way, you get fred/beta (assuming you've
added Fred's repo as a remote named "fred" ofcourse) and all your
branches have names that never (in theory) clash with any of your
upstreams.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

Considering the successes of the wars on alcohol, poverty, drugs and
terror, I think we should give some serious thought to declaring war
on peace.

Re: push.default???

[Finn Arne Gangstad]

On Tue, Jun 23, 2009 at 03:21:06PM +0200, Andreas Ericsson wrote:
> Finn Arne Gangstad wrote:
>> On Tue, Jun 23, 2009 at 02:59:10PM +0200, Paolo Bonzini wrote:
>> [...]
>>> Before going on, can you explain your use case for --push=tracking 
>>> (in a  case where --push=current wouldn't do the same)?
>>
>> The idea with "tracking" is to push the current branch to wherever it
>> would pull from, making push & pull "equivalent" in some sense.
>>
>> This is different from "current" if you have/choose to name the local
>> branch something else than the remote branch. This happens a lot when
>> using multiple remotes.
>>
>> E.g. some remotes have only a single active branch called "master",
>> and you have to name it something else locally, or several people have
>> local branches called "beta", and you have to name it something like
>> "fred-beta" locally if you are working on fred's beta.
>>
>
> Umm. Why not name it after the feature you're working on instead of the
> branch you started from? That way, you get fred/beta (assuming you've
> added Fred's repo as a remote named "fred" ofcourse) and all your
> branches have names that never (in theory) clash with any of your
> upstreams.

Maybe I misunderstand what you are saying, but: The point is that you
can not name it the same as on the remote. So the names are different,
and --current will not work.

- Finn Arne

Re: push.default???

[Andreas Ericsson]

Finn Arne Gangstad wrote:
> On Tue, Jun 23, 2009 at 03:21:06PM +0200, Andreas Ericsson wrote:
>> Finn Arne Gangstad wrote:
>>> On Tue, Jun 23, 2009 at 02:59:10PM +0200, Paolo Bonzini wrote:
>>> [...]
>>>> Before going on, can you explain your use case for --push=tracking 
>>>> (in a  case where --push=current wouldn't do the same)?
>>> The idea with "tracking" is to push the current branch to wherever it
>>> would pull from, making push & pull "equivalent" in some sense.
>>>
>>> This is different from "current" if you have/choose to name the local
>>> branch something else than the remote branch. This happens a lot when
>>> using multiple remotes.
>>>
>>> E.g. some remotes have only a single active branch called "master",
>>> and you have to name it something else locally, or several people have
>>> local branches called "beta", and you have to name it something like
>>> "fred-beta" locally if you are working on fred's beta.
>>>
>> Umm. Why not name it after the feature you're working on instead of the
>> branch you started from? That way, you get fred/beta (assuming you've
>> added Fred's repo as a remote named "fred" ofcourse) and all your
>> branches have names that never (in theory) clash with any of your
>> upstreams.
> 
> Maybe I misunderstand what you are saying, but: The point is that you
> can not name it the same as on the remote. So the names are different,
> and --current will not work.
> 

I think our workflows differ quite drastically, as I very rarely see
the need to push more than one branch. When I do, it's for repositories
where I'm the ultimate upstream, so I only have one remote that I
actually *can* push to at all.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

Considering the successes of the wars on alcohol, poverty, drugs and
terror, I think we should give some serious thought to declaring war
on peace.

Re: push.default???

[Paolo Bonzini]

Finn Arne Gangstad wrote:
> On Tue, Jun 23, 2009 at 02:59:10PM +0200, Paolo Bonzini wrote:
> [...]
>> Before going on, can you explain your use case for --push=tracking (in a  
>> case where --push=current wouldn't do the same)?
> 
> The idea with "tracking" is to push the current branch to wherever it
> would pull from, making push & pull "equivalent" in some sense.
> 
> This is different from "current" if you have/choose to name the local
> branch something else than the remote branch. This happens a lot when
> using multiple remotes.

Yes, but when using multiple remotes is it really common that:

1) I have the permission to push to them (as opposed to sending a pull 
request)?  If I have permission to push only to the mob branch, for 
example, I would still set my tracking branch to the master branch.

2) I *do* want to push to them often?  If I use tracking for my topic 
branches, push.default=tracking seems a sure way to big mess when I do 
"git push" on the wrong branch.  Instead, with push.default=current "git 
push" would just tell me "new branch created" and then I can do "git 
push branch-name:" to delete the newly created branch.

I don't remember who it was, but when I tried changing the behavior for 
"git push" someone screamed loudly that fetching and pushing are two 
different things, and making things work uniformly across the two is not 
necessarily correct.  The details probably were different, but I think 
that I am saying the same now.

Paolo

Re: push.default???

[Finn Arne Gangstad]

On Tue, Jun 23, 2009 at 03:28:04PM +0200, Paolo Bonzini wrote:
> Finn Arne Gangstad wrote:
>> On Tue, Jun 23, 2009 at 02:59:10PM +0200, Paolo Bonzini wrote:
>> [...]
>>> Before going on, can you explain your use case for --push=tracking 
>>> (in a  case where --push=current wouldn't do the same)?
>>
>> The idea with "tracking" is to push the current branch to wherever it
>> would pull from, making push & pull "equivalent" in some sense.
>>
>> This is different from "current" if you have/choose to name the local
>> branch something else than the remote branch. This happens a lot when
>> using multiple remotes.
>
> Yes, but when using multiple remotes is it really common that:
>
> 1) I have the permission to push to them (as opposed to sending a pull  
> request)?  If I have permission to push only to the mob branch, for  
> example, I would still set my tracking branch to the master branch.

I don't know how common it is, but it is certainly not unheard of. You
have a shared public server, and a group-shared public server and so
on. You only need a single shared public server for this to make sense
however.

> 2) I *do* want to push to them often?  If I use tracking for my topic  
> branches, push.default=tracking seems a sure way to big mess when I do  
> "git push" on the wrong branch.

In our shared repositories, we have a few protected branches that only
integrators can push to, so no one else can accidentally push to
them. These are typically the branches that it makes sense to track
"by default".

If a group sets up a shared public branch, it is typically for
working together on some feature. There are very few surprises if
the group works like this:

 1. Do some modifications
 2. git commit
 3. git pull [--rebase]
 4. git push
 5. goto 1 .. 

For people used to CVS, this is a nice way to start working with git.
It requires --tracking to work properly though (--current only works
if you remember to use the same branch name).

> Instead, with push.default=current "git  
> push" would just tell me "new branch created" and then I can do "git  
> push branch-name:" to delete the newly created branch.

Well, you need to add the name of the remote. And while not exactly
impossible to find, for the target audience it may be a bit more
cumbersome than it should be:

branch: git symbolic-ref HEAD | sed -e s=refs/heads/==
remote: git config branch.<branch>.remote

And if you want to figure out what the branch you pulled from is
named, you have to do something like

git config branch.<branch>.merge | sed -e s=refs/heads/==

> I don't remember who it was, but when I tried changing the behavior for  
> "git push" someone screamed loudly that fetching and pushing are two  
> different things, and making things work uniformly across the two is not  
> necessarily correct.  The details probably were different, but I think  
> that I am saying the same now.

Different use cases want different things from push. If you are the top
level integrator of a project and are trying to keep 3 remotes in sync
with your master repository, "matching" seems to be what you want.

If you are a leaf-node worker pushing to a public repository, it
isn't. But --tracking may be a valid choice sometimes (and is, in some
sense, very close to SCMs people may be used to).

- Finn Arne

Re: push.default???

[Paolo Bonzini]

>> 1) I have the permission to push to them (as opposed to sending a pull
>> request)?  If I have permission to push only to the mob branch, for
>> example, I would still set my tracking branch to the master branch.
>>
>> 2) I *do* want to push to them often?  If I use tracking for my topic
>> branches, push.default=tracking seems a sure way to big mess when I do
>> "git push" on the wrong branch.
>
> In our shared repositories, we have a few protected branches that only
> integrators can push to, so no one else can accidentally push to
> them. These are typically the branches that it makes sense to track
> "by default".

Yes, on the other hand you cannot push to them, so talking about them
in the context if push.default is moot. :-)

> If a group sets up a shared public branch, it is typically for
> working together on some feature.
>
> For people used to CVS, this is a nice way to start working with git.
> It requires --tracking to work properly though (--current only works
> if you remember to use the same branch name).

Ok, this *is* a usecase.  Your local branch is named as a feature but
it pushes into master.  Thanks, I have something to reason about now.
:-)

Paolo

Re: push.default???

[Junio C Hamano]

Paolo Bonzini <paolo.bonzini@gmail.com> writes:

>> If a group sets up a shared public branch, it is typically for
>> working together on some feature.
>>
>> For people used to CVS, this is a nice way to start working with git.
>> It requires --tracking to work properly though (--current only works
>> if you remember to use the same branch name).
>
> Ok, this *is* a usecase.  Your local branch is named as a feature but
> it pushes into master.  Thanks, I have something to reason about now.
> :-)

I actually have been having a hard time imagining how such a set-up makes
sense, even during your absense (i.e. the timeframe we did push.default).

You are forking off of shared 'master', but you are developing a feature
on a separate branch 'feature'.

That is a sane thing to do for two reasons.  (1) Until 'feature' is done
to your own satisfaction, you do not want to contaminate your own 'master'
with the half-cooked feature development in it. (2) While you are working
on 'feature', you may want to update your own 'master' from the shared
repository to monitor how others are doing.  Having a separate, pristine
'master' branch allows you to do so more easily, than detaching HEAD at
'origin/master' every once in a while.

However, when 'feature' is fully cooked, before pushing it back to be
shared with others in the group, don't you do any testing with the work
done by others while you were working on 'feature'?  That means you first
integrate your 'feature' locally into shared 'master' and make sure all
fits together well.

Until you do that, you cannot be confident that the feature you developed
is fit for public consumption.  But if you test after merging 'feature'
into 'master', what you determined as good is in 'master', which you can
push back to the remote's 'master'.

One glitch I can think of is what would happen if you do not want to merge
your feature for final testing to master, but instead rebase your feature
on top of master (let's not discuss why you should or should not rebase at
this point; some projects seem to insist you rebase and there may be no
good technical reason but that is not the topic here).  There currently is
no easy UI other than:

	$ git checkout master
        $ git pull --rebase . feature
	$ test test test
	$ git push origin master

or even worse:

	$ git checkout feature
        $ git rebase master
        $ git checkout master
        $ git merge feature
	$ test test test
	$ git push origin master

to tell git to integrate your local work done in 'feature' to 'master' by
rebasing, instead of merging.  If you do a merge, that is quite
straightforward:

	$ git checkout master
        $ git merge feature
	$ test test test
	$ git push origin master

but instead you have to do something like:

	$ git checkout feature
        $ git rebase master
        $ test test test
        $ git push origin feature:master

and you end up needing "put my 'feature' into their 'master'".

Could it be possible that this desire to push "tracking" is not a cure for
anything real, but merely a kludge to work around a misfeature of "rebase"
UI that does not allow "integrate that branch here but do not merge it but
by first rebasing it"?  In other words, if we had "git merge --rebase" (I
know, I know, it is a terrible name.  The word "merge" in this context
means "to integrate"), the above can be done more naturally:

	$ git checkout master
        $ git merge --rebase feature
	$ test test test
	$ git push origin master

and the matching push (or "git push origin HEAD") becomes the right thing
to do, eliminating the need for "put my 'feature' into their 'master'".

For a group that sets up a shared public branch to be used for working
together on some feature, replace 'master' with 'some feature' above, and
'feature' with 'your part of the work on the feature'; the story is the
same.

Re: push.default???

[Junio C Hamano]

Junio C Hamano <gitster@pobox.com> writes:

> One glitch I can think of is what would happen if you do not want to merge
> your feature for final testing to master, but instead rebase your feature
> on top of master (let's not discuss why you should or should not rebase at
> this point; some projects seem to insist you rebase and there may be no
> good technical reason but that is not the topic here).  There currently is
> no easy UI other than:
>
>       $ git checkout master
>       $ git pull --rebase . feature
>       $ test test test
>       $ git push origin master
> ...
> to tell git to integrate your local work done in 'feature' to 'master' by
> rebasing, instead of merging.

Sorry, but I screwed up.  The above rebases 'master', so it does not do
what we want to do.  The only way I can think of is:

> or even worse:
>
>       $ git checkout feature
>       $ git rebase master
>       $ git checkout master
>       $ git merge feature
>       $ test test test
>       $ git push origin master

which is too much typing.  That makes my suspicion that the conclusion of
my previous message is correct even stronger.

> Could it be possible that this desire to push "tracking" is not a cure for
> anything real, but merely a kludge to work around a misfeature of "rebase"
> UI that does not allow "integrate that branch here but do not merge it but
> by first rebasing it"?  In other words, if we had "git merge --rebase" (I
> know, I know, it is a terrible name.  The word "merge" in this context
> means "to integrate"), the above can be done more naturally:
>
>       $ git checkout master
>       $ git merge --rebase feature
>       $ test test test
>       $ git push origin master
>
> and the matching push (or "git push origin HEAD") becomes the right thing
> to do, eliminating the need for "put my 'feature' into their 'master'".
>
> For a group that sets up a shared public branch to be used for working
> together on some feature, replace 'master' with 'some feature' above, and
> 'feature' with 'your part of the work on the feature'; the story is the
> same.

Re: push.default???

[Miles Bader]

Junio C Hamano <gitster@pobox.com> writes:
> However, when 'feature' is fully cooked, before pushing it back to be
> shared with others in the group, don't you do any testing with the work
> done by others while you were working on 'feature'?  That means you first
> integrate your 'feature' locally into shared 'master' and make sure all
> fits together well.

You seem to be making a lot of assumptions about workflows here.

It seems quite plausible to me that one might want to keep the remote
branch separate, even after pushing.  It's very common to cooperatively
develop feature branches for a very long time before merging to the
"real" master, but it's still extremely useful to keep them as branches
in the same local git directory.

-Miles

-- 
Somebody has to do something, and it's just incredibly pathetic that it
has to be us.  -- Jerry Garcia

Re: push.default???

[Junio C Hamano]

Miles Bader <miles@gnu.org> writes:

> Junio C Hamano <gitster@pobox.com> writes:
>> However, when 'feature' is fully cooked, before pushing it back to be
>> shared with others in the group, don't you do any testing with the work
>> done by others while you were working on 'feature'?  That means you first
>> integrate your 'feature' locally into shared 'master' and make sure all
>> fits together well.
>
> You seem to be making a lot of assumptions about workflows here.
>
> It seems quite plausible to me that one might want to keep the remote
> branch separate, even after pushing.  It's very common to cooperatively
> develop feature branches for a very long time before merging to the
> "real" master, but it's still extremely useful to keep them as branches
> in the same local git directory.

Sorry, but I do not understand your point.

My "feature is cooked, let's test it together with master" does not mean
"Now we are done with the feature, so let's 'branch -d' it" at all.  That
is an orthogonal issue.  You can keep 'feature' in the local repository
indefinitely.

Keeping the remote branch separate means pushing 'feature' to 'feature',
and keep it there.  I do not have any problem with that, either.

The '--track' I was having hard time justifying to myself was about
pushing 'feature' (and other features 'feature2', 'feature3',... that are
all forked from 'master' at the remote side) to 'master' at remote.  In
other words, the workflow being discussed to support why --track was a
good mode was about updating the remote 'master', not about keeping the
branches separate.

Either you are not following the thread, or you are agreeing with me
without realizing, or perhaps a bit of both.

Re: push.default???

[Paolo Bonzini]

> You are forking off of shared 'master', but you are developing a feature
> on a separate branch 'feature'.
> 
> However, when 'feature' is fully cooked, before pushing it back to be
> shared with others in the group, don't you do any testing with the work
> done by others while you were working on 'feature'?  That means you first
> integrate your 'feature' locally into shared 'master' and make sure all
> fits together well.
> 
> Until you do that, you cannot be confident that the feature you developed
> is fit for public consumption.  But if you test after merging 'feature'
> into 'master', what you determined as good is in 'master', which you can
> push back to the remote's 'master'.

Here is what I think you are missing: in the proposed workflow, there is 
an entire group working on one big feature, so there is effectively one 
remote per feature.

In fact, what was not clear to me before Finn explained it is the way 
these remotes are configured and mapped to local branches.  In his 
setup, your own master branch is tracking integration/master, but your 
feature branch is tracking feature/master.  You're effectively using a 
centralized repository but splitting it across several remotes, 
presumably for two reasons: 1) access control, 2) so that people can 
choose which parts of the repository to mirror.

Mind that this is quite a mangled DVCS workflow :-) since you're 
distributing the centralized repository (!), so you're not using topic 
branches and you're not committing very often; if you were using topic 
branches you would have to use --no-track or risk pushing by mistake to 
feature/master.  You just map "svn update" to "git pull --rebase" and 
"svn commit" to "git commit + git push".

So, every time you finish some aspect of 'feature', you rebase it on top 
of the tracked branch feature/master to test it with the work done by 
others, and then push.  The rebasing is taken care of by "git pull", so 
it makes sense in this case that pushing to feature/master is done with 
plain "git push".

> Could it be possible that this desire to push "tracking" is not a cure for
> anything real, but merely a kludge to work around a misfeature of "rebase"
> UI that does not allow "integrate that branch here but do not merge it but
> by first rebasing it"?  In other words, if we had "git merge --rebase feature"
> [to merge rebased feature into master, then "git push origin HEAD"] becomes the
 > right thing to do, eliminating the need for "put my 'feature' into 
their 'master'".
 >
> For a group that sets up a shared public branch to be used for working
> together on some feature, replace 'master' with 'some feature' above, and
> 'feature' with 'your part of the work on the feature'; the story is the
> same.

I think this makes sense, but it is not what Finn was going after.  In 
his setup, there is no 'your part of the work on the feature', 
everything is done in a single branch.


Now, here is a plan to realize the same workflow with a different 
implementation.

1) introduce a new configuration key branch.autosetuppush that 
automatically adds a remote.*.push entry whenever a tracking branch is 
created.

I think this is also the right time to introduce per-remote autosetup 
keys remote.*.autosetup{merge,rebase,push}.  In fact I would introduce 
these per-remote configurations before, as a kind of "step 0".

2) introduce git push --current (or maybe --head-only) that uses 
whatever refspec "git push" uses, but always restrict pushing to the 
current branch.  This would only apply to "git push" without explicit 
refspecs.

3) introduce remote.*.pushHeadOnly to make "git push" always behave like 
"git push --current".

Note that the new command line option is not really needed, but it would 
make testing harder if --current behavior could be specified only with 
configuration keys.

4) introduce a --push option for "git remote add".  Every push.default 
configuration, thanks to steps 1 and 3, now maps to a simple configuration:

  --push=current -> remote.*.push = HEAD
  --push=tracking -> remote.*.autosetuppush=remote.*.pushHeadOnly=true
  --push=matching -> remote.*.push = :

In addition, --push=mirror could be implemented to do the same as --mirror.


I have a rough draft of all but the last step already implemented (I 
have not even compiled, but I wanted to measure roughly the complexity 
of the features; unless I screwed up big, it seems like a "calm" patch 
series).  I like this way more than the "magic refspec".  Unlike 
push.default, it builds entirely on the concept of refspecs.  But unlike 
the magic refspec, it fits with the rest of --track better, and it just 
uses two easily understood knobs to achieve its objective.

Paolo

Re: push.default???

[Finn Arne Gangstad]

On Wed, Jun 24, 2009 at 10:50:00AM +0200, Paolo Bonzini wrote:
>
> Here is what I think you are missing: in the proposed workflow, there is  
> an entire group working on one big feature, so there is effectively one  
> remote per feature.

I think you are making this more complicated than it is. I just claim
that the idea that "branch names must be identical in both ends" is
not necessarily the best model.

In a sufficiently large origanisation with multiple levels of
repositories (access restrictions, locality, whatever) branch names
are not globally unique, and there is no reasonable way to check if a
branch name is used elsewhere. It is much easier to treat local branch
names as strictly local, and worry about naming (only) when you push
somewhere.

So - even if someone decided to name something "issue-331318" on a
public repository, it doesn't mean you want to call it that locally,
even if you want to push to it.

If a branch already exists on a public repo, it doesn't mean a branch
with the same name but with different contents/purpose cannot exist in
a different repo. So you may have to name the branch something else
locally. Pull knows how to deal with this, but push did not (before
"--tracking").

Another example:

You have worked for a few days on an issue, but need help from someone
else with something. You have set up a public shared repo named
"public", and do:

git push public HEAD:fred-helpme

Fred wants to name it something else that makes him remember what this
branch is about, and does:

git fetch public
git checkout -b tmp-help-john public/fred-helpme
<hack hack>
git commit
git push   (no more arguments, and no need to remember what it was named)

You then fetch and look at what Fred has done, and maybe you just use
it, or maybe you don't. Afterwards git push public :fred-helpme to get
rid of the temporary shared branch.

- Finn Arne