Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Philip Oakley

From: "Junio C Hamano" 
Sent: Friday, May 24, 2013 5:26 PM

Felipe Contreras  writes:


... but I don't see why something small like that
wouldn't make sense:

The pull was not fast-forward, please either merge or rebase.


OK, I think I got what John was getting at and this single liner
message is a good summary of it.

Instead of telling them "you cannot push this thing without losing
history from the location you are pushing to; you need to become up
to date with respect to them before pushing" upon seeing a non ff
push failure, we can tell them "you cannot update your history to
what the place you get new changes from has without losing your
history; you need to integrate the two".

Initially I said limiting "git pull" to "--ff-only" by default did
not make sense, but when we view it that way, I now see how such a
default makes sense.

In another subthread, John Szakmeister mentioned that the "please
'git pull' first" message that a "push" gives when it stops due to
non-ff nudges the users in a wrong direction, because they often
take that 'git pull' too literally (e.g. 'pull --rebase' may be
necessary in their project, not 'git pull').

The original message deliberately avoided mentioning 'git pull' for
that exact reason, but in mid 2010 we made it worse.  The log of
that change says that it attempted to

   ... remains fuzzy to include "git pull", "git pull --rebase" and
   others, but directs the user to the simplest solution in the
   vast majority of cases.

but this thread shows that it did not work; the simplest solution
was a wrong one.  The message also may need to be rethought to
complement this direction being proposed for "pull".
--


Perhaps offer "git pull ", which suggests that the user should 
consider what pull parameters to provide and if taken literally should 
barf with the four dots.


Philip

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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Junio C Hamano
Andreas Krey  writes:

> On Thu, 23 May 2013 09:01:15 +, Junio C Hamano wrote:
> ...
>> Instead of having a nice "these six commits marked as 'x' were done
>> on a branch forked some time ago, to address only this one issue and
>> to address it fully" history that explains how these commits were
>> related and these commits are the full solution to a single issue:
>> 
>>   x---x---x---x---x---x
>>  / \
>>  ---o---o---o---o---o---o---M---o---o---...
>> 
>> they end up with something like this, even with the "flip the heads
>> of a merge" option, by pulling too often:
>> 
>>   x---x   x---x---x   x
>>  / \ / \ / \
>>  ---o---o---M---o---o---M---M---o---o---...
>
> Wouldn't that be (you don't want to put your work back into master before
> it's done) the following?
>
>x---x---M---x---x---M--x
>   /   /   /\
>   ---o---o---M---o---o---M--o---M---o---o---...

That is what you would get if you "pull from my upstream" with the
current software.

And that is what triggered this discussion thread in which some
people said that they do not want that shape of the history.

At the leftmost merge M you drew on the upper line (i.e. your
topic), the merge pulls in other's commits that are unrelated to
each other as if it were a meaningful group of commits on a side
branch.  They want to see the merge going other way around, pulling
your work done on a side branch, integrating into the mainline.

The second illustration you are commenting on were done to explain
why such a "when pulling from my upstream, I want the order of
parents swapped, so that mainline appears as the first parent" is
not solving the whole issue.  The time series would go more like
this:

(1) While you were working on two 'x's, others have worked to
advance the mainline:

   x---x  Your 'master'
  /
  ---o---o  Mainline


(2) You cannot push without losing others work, so you pull, but in
order to avoid the "others work on mixed on a single side
branch" issue, you use the fictional "flip heads of a merge"
option, and push the result out.  That becomes the tip of the
mainline:

   x---x
  / \
  ---o---o---M

(3) Then you keep working to build more commits on top. 

   x---x   x---x---x
  / \ /
  ---o---o---M

(4) And others also keep working.

   x---x   x---x---x
  / \ /
  ---o---o---M---o---o

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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Andreas Krey
On Fri, 24 May 2013 17:05:26 +, Holger Hellmuth (IKS) wrote:
> Am 24.05.2013 15:42, schrieb Andreas Krey:
...
> >The branch name is almost completely meaningless. I could just
> >do my feature in my local master and never have a different name.
> 
> In which case parent switching in the commit wouldn't help you either.

Oh, it does; I tried. Names are meaningless, the parent ordering
isn't. ( [And at least, it's already in there.]

> But even you could keep your master always on the left side of gitk if 
> you deem it special. And you could keep longer running cooperative 
> branches (the main develop and the release branch of your project for 
> example) in a seperate lane.

I need gitk (or similar) to do it. Will take some time to understand
the code (and triggers the 'I can write it (the interesting part) faster
than I can grok gitk').

...
> Without additional information about the commit history gitk can do 
> exactly what it does now.

Most definitely not. There are quite some situations where the graph
deteriorates pretty heavily, even when not expecting it to pay attention
to first parent. When you have two branches, of which one regularly
gets merge into the other, it sometimes manages to display first the
one, then the other branch, with a log of merge edges going upwards
in parallel, for example.

Andreas

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Andreas Krey
On Thu, 23 May 2013 09:01:15 +, Junio C Hamano wrote:
...
> Instead of having a nice "these six commits marked as 'x' were done
> on a branch forked some time ago, to address only this one issue and
> to address it fully" history that explains how these commits were
> related and these commits are the full solution to a single issue:
> 
>   x---x---x---x---x---x
>  / \
>  ---o---o---o---o---o---o---M---o---o---...
> 
> they end up with something like this, even with the "flip the heads
> of a merge" option, by pulling too often:
> 
>   x---x   x---x---x   x
>  / \ / \ / \
>  ---o---o---M---o---o---M---M---o---o---...

Wouldn't that be (you don't want to put your work back into master before
it's done) the following?

   x---x---M---x---x---M--x
  /   /   /\
  ---o---o---M---o---o---M--o---M---o---o---...

With a bit of luck the first-parent strands will also run like this.

I know that rebasing topic branches is better than updating, but my
monetary upstream is busy letting go a clearcase-minted mindset.
Teaching them rebasing will take a while, and as long as tthat we
will have the picture above.

Andreas

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Junio C Hamano
Felipe Contreras  writes:

> ... but I don't see why something small like that
> wouldn't make sense:
>
> The pull was not fast-forward, please either merge or rebase.

OK, I think I got what John was getting at and this single liner
message is a good summary of it.

Instead of telling them "you cannot push this thing without losing
history from the location you are pushing to; you need to become up
to date with respect to them before pushing" upon seeing a non ff
push failure, we can tell them "you cannot update your history to
what the place you get new changes from has without losing your
history; you need to integrate the two".

Initially I said limiting "git pull" to "--ff-only" by default did
not make sense, but when we view it that way, I now see how such a
default makes sense.

In another subthread, John Szakmeister mentioned that the "please
'git pull' first" message that a "push" gives when it stops due to
non-ff nudges the users in a wrong direction, because they often
take that 'git pull' too literally (e.g. 'pull --rebase' may be
necessary in their project, not 'git pull').

The original message deliberately avoided mentioning 'git pull' for
that exact reason, but in mid 2010 we made it worse.  The log of
that change says that it attempted to

... remains fuzzy to include "git pull", "git pull --rebase" and
others, but directs the user to the simplest solution in the
vast majority of cases.

but this thread shows that it did not work; the simplest solution
was a wrong one.  The message also may need to be rethought to
complement this direction being proposed for "pull".
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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Holger Hellmuth (IKS)

Am 24.05.2013 15:42, schrieb Andreas Krey:

On Fri, 24 May 2013 11:29:00 +, Holger Hellmuth (IKS) wrote:
...

Here is an idea (probably already discussed in the long history of git):
1) the branch name is recorded in a commit (for merges the branch that
is updated)


The branch name is almost completely meaningless. I could just
do my feature in my local master and never have a different name.


In which case parent switching in the commit wouldn't help you either.

But even you could keep your master always on the left side of gitk if 
you deem it special. And you could keep longer running cooperative 
branches (the main develop and the release branch of your project for 
example) in a seperate lane.


Depending on your use of branches many branches won't get any ordering, 
but at a minimum important branches can easily be "highlighted".



Or commit something onto tmp that I then fast-forward into my
(properly named) feature branch.


Yes, but then you would see a feature branch in its expected column in 
gitk and you would also see (even years later) that it didn't start as a 
feature but later was made into one. Cues like this help to remember 
what happened even if you forgot to mention them in the commit message



2) unique identifier of repository is recorded in commit (optional)


That is pure noise (in my workflow).


It is important to differentiate between branches of the same name in 
different repositories. For example if your project has a central 
repository with master getting all the release stuff you want to sort 
that master differently than your own master.


The unique identifier might be just a random number or string created at 
init time of the repo.



3) simple configurable ordering and/or coloring scheme in gitk based on
committer,branch name and repo (with wildcards).


Ok, gitk could use some features. :-)


Without additional information about the commit history gitk can do 
exactly what it does now.



...

Is this a bad idea or just no one did it yet?


Possibly not bad (hg does parts of it), but un-git-ish?


Don't know. No CVS does branches as good as git. But then it drops that 
information which depending on development style could be useful or not.
Not that useful for people who keep their history clean, a lot for 
people who don't.



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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Andreas Krey
On Fri, 24 May 2013 11:29:00 +, Holger Hellmuth (IKS) wrote:
...
> Here is an idea (probably already discussed in the long history of git):
> 1) the branch name is recorded in a commit (for merges the branch that 
> is updated)

The branch name is almost completely meaningless. I could just
do my feature in my local master and never have a different name.

Or commit something onto tmp that I then fast-forward into my
(properly named) feature branch.

> 2) unique identifier of repository is recorded in commit (optional)

That is pure noise (in my workflow).

> 3) simple configurable ordering and/or coloring scheme in gitk based on 
> committer,branch name and repo (with wildcards).

Ok, gitk could use some features. :-)

...
> Is this a bad idea or just no one did it yet?

Possibly not bad (hg does parts of it), but un-git-ish?

(I'm not sure that it was *intended* that the parents
of a merge commit have an order, except that they need
to for deterministic hashes.)

Andreas

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread John Szakmeister
On Fri, May 24, 2013 at 4:29 AM, John Keeping  wrote:
[snip]
> Note that in my email that started this, I tried to be clear that I was
> talking about "git pull" *without a branch name*.  If this user
> explicitly says "git pull remote branch" then I consider that a clear
> indication that they really do mean to perform a merge; I would not
> recommend changing the current behaviour in that case.
>
> If the user just says "git pull" then it is more likely that they are
> just trying to synchronise with the upstream branch, in which case they
> probably don't actually want a merge.

This makes a lot of sense to me.  I was going to write earlier that I
almost wish there was a separate command for getting your local branch
"in sync" with the remote one.

BTW, it also doesn't help that `git pull` is suggested as the answer
anytime a push cannot succeed.  I've warned my users about using `git
pull`, and--unfortunately--they sometimes forget because the advice is
right there in front of them.

I agree with John here: it's a bare `git pull` that is often the
culprit.  Of course, the asymmetry between `git pull` and `git pull
remote branch` is a little bothersome too, but the team does that
*far* less often.

-John
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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread Holger Hellmuth (IKS)

Am 23.05.2013 21:25, schrieb Andreas Krey:

On Thu, 23 May 2013 11:06:57 +, Andreas Krey wrote:
...

...

Don't do that, then.


Ouch, you're right. The problem is not actually in the
pull; only the *last* pull into a feature branch that
then get pushed back ff to master needs to be reversed.

And at that time you don't know it's the last one
-> swap parents before the push if necessary.


if you have to be so careful to ensure the correct ordering of parents 
it almost defeats the initial objective to make commit graphs in gitk 
look nice without re-educating/restricting other users. A solution that 
works for everyone should work without users having to think about it.


Here is an idea (probably already discussed in the long history of git):
1) the branch name is recorded in a commit (for merges the branch that 
is updated)

2) unique identifier of repository is recorded in commit (optional)
3) simple configurable ordering and/or coloring scheme in gitk based on 
committer,branch name and repo (with wildcards).


With this users could pull and push as often as they like, the main 
branches would always be ordered and straight lines. If instead you 
already do the work to keep your history clean you could just use the 
coloring scheme and see committers color coded in gitk. Further benefit: 
the history of really old commits could be more easily remembered if you 
knew in what branch they originated


Is this a bad idea or just no one did it yet?

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Re: first parent, commit graph layout, and pull merge direction

2013-05-24 Thread John Keeping
On Thu, May 23, 2013 at 06:53:36PM -0500, Felipe Contreras wrote:
> The alternatives are these:
> 
> a) you annoy the vast majority of the user-base by making 'git pull' a
> dangerous operation that should be avoided, and replaced with 'git
> fetch'+'git rebase'.
> 
> b) you annoy a minority of the user-base by making 'git pull' not do
> the merge the expected, so they have to do +'git merge' (which is
> already less of a change than a)), or configure the default (which
> they most likely are able to do, if they did intent to do a merge).

Note that in my email that started this, I tried to be clear that I was
talking about "git pull" *without a branch name*.  If this user
explicitly says "git pull remote branch" then I consider that a clear
indication that they really do mean to perform a merge; I would not
recommend changing the current behaviour in that case.

If the user just says "git pull" then it is more likely that they are
just trying to synchronise with the upstream branch, in which case they
probably don't actually want a merge.
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Felipe Contreras
On Thu, May 23, 2013 at 7:25 PM, Felipe Contreras
 wrote:
> On Thu, May 23, 2013 at 7:21 PM, Junio C Hamano  wrote:
>> Linus Torvalds  writes:
>>
>>> It would be a *horrible* mistake to make "rebase" the default, because
>>> it's so much easier to screw things up that way.
>>>
>>> That said, making "no-ff" the default, and then if that fails, saying
>>>
>>>The pull was not a fast-forward pull, please say if you want to
>>> merge or rebase.
>>>Use either
>>>
>>> git pull --rebase
>>> git pull --merge
>>>
>>>You can also use "git config pull.merge true" or "git config
>>> pull.rebase true"
>>>to set this once for this project and forget about it.
>>>
>>> That way, people who want the existing behavior could just do that
>>>
>>> git config pull.merge true
>>>
>>> once, and they'd not even notice.
>>>
>>> Hmm? Better yet, make it per-branch.
>>
>> I would assume that "no-ff" above was meant to be "--ff-only" from
>> the first part of the message.
>>
>> I also would assume that I can rephrase that setting pull.merge
>> (which does not exist) as setting pull.rebase explicitly to false
>> instead (i.e. missing pull.rebase and pull.rebase that is explicitly
>> set to false would mean two different things).
>>
>> I have to think about this a bit to convince myself that the message
>> is clear enough and useful for those this updated behaviour is
>> trying to help.  After reading the above message three times, I
>> still cannot shake the impression that we are just covering our
>> backside to be able to say "we told you already and you chose
>> poorly", in case things go wrong for them later.
>
> FWIW this is the message Mercurial users get (and they often say
> Mercurial's UI makes more sense):
>
> pushing to /tmp/foo
> searching for changes
> abort: push creates new remote head 77eafc4313d5!
> (you should pull and merge or use push -f to force)

Er, that's for push, but I don't see why something small like that
wouldn't make sense:

The pull was not fast-forward, please either merge or rebase.

-- 
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Felipe Contreras
On Thu, May 23, 2013 at 7:21 PM, Junio C Hamano  wrote:
> Linus Torvalds  writes:
>
>> It would be a *horrible* mistake to make "rebase" the default, because
>> it's so much easier to screw things up that way.
>>
>> That said, making "no-ff" the default, and then if that fails, saying
>>
>>The pull was not a fast-forward pull, please say if you want to
>> merge or rebase.
>>Use either
>>
>> git pull --rebase
>> git pull --merge
>>
>>You can also use "git config pull.merge true" or "git config
>> pull.rebase true"
>>to set this once for this project and forget about it.
>>
>> That way, people who want the existing behavior could just do that
>>
>> git config pull.merge true
>>
>> once, and they'd not even notice.
>>
>> Hmm? Better yet, make it per-branch.
>
> I would assume that "no-ff" above was meant to be "--ff-only" from
> the first part of the message.
>
> I also would assume that I can rephrase that setting pull.merge
> (which does not exist) as setting pull.rebase explicitly to false
> instead (i.e. missing pull.rebase and pull.rebase that is explicitly
> set to false would mean two different things).
>
> I have to think about this a bit to convince myself that the message
> is clear enough and useful for those this updated behaviour is
> trying to help.  After reading the above message three times, I
> still cannot shake the impression that we are just covering our
> backside to be able to say "we told you already and you chose
> poorly", in case things go wrong for them later.

FWIW this is the message Mercurial users get (and they often say
Mercurial's UI makes more sense):

pushing to /tmp/foo
searching for changes
abort: push creates new remote head 77eafc4313d5!
(you should pull and merge or use push -f to force)

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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Linus Torvalds
On Thu, May 23, 2013 at 5:21 PM, Junio C Hamano  wrote:
>
> I would assume that "no-ff" above was meant to be "--ff-only" from
> the first part of the message.

Yeah, I may need more coffee..

> I also would assume that I can rephrase that setting pull.merge
> (which does not exist) as setting pull.rebase explicitly to false
> instead (i.e. missing pull.rebase and pull.rebase that is explicitly
> set to false would mean two different things).

Yeah, sounds good to me, and doesn't really sound like it would
confuse/annoy anybody as long as it was clearly documented.

  Linus
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Junio C Hamano
Linus Torvalds  writes:

> It would be a *horrible* mistake to make "rebase" the default, because
> it's so much easier to screw things up that way.
>
> That said, making "no-ff" the default, and then if that fails, saying
>
>The pull was not a fast-forward pull, please say if you want to
> merge or rebase.
>Use either
>
> git pull --rebase
> git pull --merge
>
>You can also use "git config pull.merge true" or "git config
> pull.rebase true"
>to set this once for this project and forget about it.
>
> That way, people who want the existing behavior could just do that
>
> git config pull.merge true
>
> once, and they'd not even notice.
>
> Hmm? Better yet, make it per-branch.

I would assume that "no-ff" above was meant to be "--ff-only" from
the first part of the message.

I also would assume that I can rephrase that setting pull.merge
(which does not exist) as setting pull.rebase explicitly to false
instead (i.e. missing pull.rebase and pull.rebase that is explicitly
set to false would mean two different things).

I have to think about this a bit to convince myself that the message
is clear enough and useful for those this updated behaviour is
trying to help.  After reading the above message three times, I
still cannot shake the impression that we are just covering our
backside to be able to say "we told you already and you chose
poorly", in case things go wrong for them later.

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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Linus Torvalds
On Thu, May 23, 2013 at 3:11 PM, Junio C Hamano  wrote:
>
> If the proposal were to make pull.rebase the default at a major
> version bump and force all integrators and other people who are
> happy with how "pull = fetch + merge" (not "fetch + rebase") works
> to say "pull.rebase = false" in their configuration, I think I can
> see why some people may think it makes sense, though.
>
> But neither is an easy sell, I would imagine.  It is not about
> passing me, but about not hurting users like kernel folks we
> accumulated over 7-8 years.

It would be a *horrible* mistake to make "rebase" the default, because
it's so much easier to screw things up that way.

That said, making "no-ff" the default, and then if that fails, saying

   The pull was not a fast-forward pull, please say if you want to
merge or rebase.
   Use either

git pull --rebase
git pull --merge

   You can also use "git config pull.merge true" or "git config
pull.rebase true"
   to set this once for this project and forget about it.

That way, people who want the existing behavior could just do that

git config pull.merge true

once, and they'd not even notice.

Hmm? Better yet, make it per-branch.

   Linus
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Felipe Contreras
On Thu, May 23, 2013 at 6:26 PM, Junio C Hamano  wrote:
> Felipe Contreras  writes:
>
> Unless your primary user base is those who use Git as a deployment
> tool to always follow along the tip of some external repository
> without doing anything on your own on the branch you run your "git
> pull" on, defaulting it to --ff-only does not make much sense to me.

 A lot of people do stuff, but the rebase it.
>>>
>>> If I am parsing the above properly, I think that is only saying that
>>> "pull --rebase" makes sense for people who do real work, which I am
>>> not disagreeing.
>>
>> You claimed that 'git pull' (--ff-only) only makes sense if the
>> primary user-base doesn't do any work on it, but that's not true; they
>> can do a 'git rebase' after such pull (or a merge).
>
> Either you misread what I wrote or I was unclear.  I really meant
> "anything on your own *ON* THE BRANCH YOU RUN your "git pull" on".
> With
>
> git checkout frotz ; git pull --ff-only
>
> you do not do anything "on frotz" other than following along.  You
> can of course commit, rebase and all others on other branches like
> xyzzy and push them out directly.  But you cannot even do this once
>
> git checkout frotz; git merge xyzzy
>
> if you expect the next "git checkout frotz; git pull --ff-only" will
> keep working usefuly.

Unless you rebase. We could of course have a
'branch..allow_merge' configuration that gets automatically
turned on the first time a 'git merge' is executed, but I feel that
creates more inconsistency.

>> We don't have to assume our primary user-base wants to do full fledged
>> merges, in fact, such assumption would be wrong.
>
> I think we are in agreement on that point already.
>
> An assumption that people who do merges are somehow more well versed
> in Git and are more capable than others to configure their
> repository or they will not be annoyed if you asked them a single
> configuration change is also wrong, though.

s/people who do merges/people who should do merges/

And no, it's not wrong. People who do merges should know what they are doing.

The alternatives are these:

a) you annoy the vast majority of the user-base by making 'git pull' a
dangerous operation that should be avoided, and replaced with 'git
fetch'+'git rebase'.

b) you annoy a minority of the user-base by making 'git pull' not do
the merge the expected, so they have to do +'git merge' (which is
already less of a change than a)), or configure the default (which
they most likely are able to do, if they did intent to do a merge).

b) is clearly superior.

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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Junio C Hamano
Felipe Contreras  writes:

 Unless your primary user base is those who use Git as a deployment
 tool to always follow along the tip of some external repository
 without doing anything on your own on the branch you run your "git
 pull" on, defaulting it to --ff-only does not make much sense to me.
>>>
>>> A lot of people do stuff, but the rebase it.
>>
>> If I am parsing the above properly, I think that is only saying that
>> "pull --rebase" makes sense for people who do real work, which I am
>> not disagreeing.
>
> You claimed that 'git pull' (--ff-only) only makes sense if the
> primary user-base doesn't do any work on it, but that's not true; they
> can do a 'git rebase' after such pull (or a merge).

Either you misread what I wrote or I was unclear.  I really meant
"anything on your own *ON* THE BRANCH YOU RUN your "git pull" on".
With

git checkout frotz ; git pull --ff-only

you do not do anything "on frotz" other than following along.  You
can of course commit, rebase and all others on other branches like
xyzzy and push them out directly.  But you cannot even do this once

git checkout frotz; git merge xyzzy

if you expect the next "git checkout frotz; git pull --ff-only" will
keep working usefuly.


> We don't have to assume our primary user-base wants to do full fledged
> merges, in fact, such assumption would be wrong.

I think we are in agreement on that point already.

An assumption that people who do merges are somehow more well versed
in Git and are more capable than others to configure their
repository or they will not be annoyed if you asked them a single
configuration change is also wrong, though.


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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Felipe Contreras
On Thu, May 23, 2013 at 5:54 PM, Junio C Hamano  wrote:
> Felipe Contreras  writes:
>
>> On Thu, May 23, 2013 at 5:11 PM, Junio C Hamano  wrote:
>>> John Keeping  writes:
>>>
 This isn't about "swap parents", it's about helping people realise that
 just "git pull" isn't necessarily the best thing for them to do, and
 that they may want --rebase.

 So I was asking if it would be sensible (possibly in Git 2.0) to make
 git-pull pass --ff-only to git-merge by default.
>>>
>>> Unless your primary user base is those who use Git as a deployment
>>> tool to always follow along the tip of some external repository
>>> without doing anything on your own on the branch you run your "git
>>> pull" on, defaulting it to --ff-only does not make much sense to me.
>>
>> A lot of people do stuff, but the rebase it.
>
> If I am parsing the above properly, I think that is only saying that
> "pull --rebase" makes sense for people who do real work, which I am
> not disagreeing.

You claimed that 'git pull' (--ff-only) only makes sense if the
primary user-base doesn't do any work on it, but that's not true; they
can do a 'git rebase' after such pull (or a merge).

We don't have to assume our primary user-base wants to do full fledged
merges, in fact, such assumption would be wrong.

>>> If the proposal were to make pull.rebase the default at a major
>>> version bump and force all integrators and other people who are
>>> happy with how "pull = fetch + merge" (not "fetch + rebase") works
>>> to say "pull.rebase = false" in their configuration, I think I can
>>> see why some people may think it makes sense, though.
>>
>> That makes perfect sense, because the people that are not familiar
>> with Git more often than not end up making merges by mistake, and the
>> ones that are familiar with it can easily configure it to do what they
>> want
>
> Yes, in theory.  The transition needs a major version bump, but it
> is doable (with unknown level of resistance).

Isn't that what wer are discussing here?

>>> But neither is an easy sell, I would imagine.  It is not about
>>> passing me, but about not hurting users like kernel folks we
>>> accumulated over 7-8 years.
>>
>> I've worked in the Linux kernel, and in my experience the vast vast
>> majority of kernel developers don't do merges; they send patches. It's
>> only the lieutenants that might do that, and although there are a lot,
>> they don't surpass the 200, and they most definitely know how to
>> configure Git to do what they need. And even then, most of them don't
>> do merges, but create a linear history for Linus to merge.
>>
>> So the only one who does really rely on merges is Linus, I think he
>> would have no problems configuring Git.
>
> That is not something I can agree or disagree without looping
> somebody whose judgement I can trust from the kernel circle ;-).

See section 16) in Documentation/SubmittingPatches, notice how the
whole section is written with Linus in mind. Some maintainers do have
sub-maintainers that send pull requests to them, not Linus, but they
are the minority. But most definitely pull requests are not for the
general population (except in a few very rare exceptions maybe).

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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Junio C Hamano
Felipe Contreras  writes:

> On Thu, May 23, 2013 at 5:11 PM, Junio C Hamano  wrote:
>> John Keeping  writes:
>>
>>> This isn't about "swap parents", it's about helping people realise that
>>> just "git pull" isn't necessarily the best thing for them to do, and
>>> that they may want --rebase.
>>>
>>> So I was asking if it would be sensible (possibly in Git 2.0) to make
>>> git-pull pass --ff-only to git-merge by default.
>>
>> Unless your primary user base is those who use Git as a deployment
>> tool to always follow along the tip of some external repository
>> without doing anything on your own on the branch you run your "git
>> pull" on, defaulting it to --ff-only does not make much sense to me.
>
> A lot of people do stuff, but the rebase it.

If I am parsing the above properly, I think that is only saying that
"pull --rebase" makes sense for people who do real work, which I am
not disagreeing.

>> If the proposal were to make pull.rebase the default at a major
>> version bump and force all integrators and other people who are
>> happy with how "pull = fetch + merge" (not "fetch + rebase") works
>> to say "pull.rebase = false" in their configuration, I think I can
>> see why some people may think it makes sense, though.
>
> That makes perfect sense, because the people that are not familiar
> with Git more often than not end up making merges by mistake, and the
> ones that are familiar with it can easily configure it to do what they
> want

Yes, in theory.  The transition needs a major version bump, but it
is doable (with unknown level of resistance).

>> But neither is an easy sell, I would imagine.  It is not about
>> passing me, but about not hurting users like kernel folks we
>> accumulated over 7-8 years.
>
> I've worked in the Linux kernel, and in my experience the vast vast
> majority of kernel developers don't do merges; they send patches. It's
> only the lieutenants that might do that, and although there are a lot,
> they don't surpass the 200, and they most definitely know how to
> configure Git to do what they need. And even then, most of them don't
> do merges, but create a linear history for Linus to merge.
>
> So the only one who does really rely on merges is Linus, I think he
> would have no problems configuring Git.

That is not something I can agree or disagree without looping
somebody whose judgement I can trust from the kernel circle ;-).
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Felipe Contreras
On Thu, May 23, 2013 at 5:11 PM, Junio C Hamano  wrote:
> John Keeping  writes:
>
>> This isn't about "swap parents", it's about helping people realise that
>> just "git pull" isn't necessarily the best thing for them to do, and
>> that they may want --rebase.
>>
>> So I was asking if it would be sensible (possibly in Git 2.0) to make
>> git-pull pass --ff-only to git-merge by default.
>
> Unless your primary user base is those who use Git as a deployment
> tool to always follow along the tip of some external repository
> without doing anything on your own on the branch you run your "git
> pull" on, defaulting it to --ff-only does not make much sense to me.

A lot of people do stuff, but the rebase it.

> If the proposal were to make pull.rebase the default at a major
> version bump and force all integrators and other people who are
> happy with how "pull = fetch + merge" (not "fetch + rebase") works
> to say "pull.rebase = false" in their configuration, I think I can
> see why some people may think it makes sense, though.

That makes perfect sense, because the people that are not familiar
with Git more often than not end up making merges by mistake, and the
ones that are familiar with it can easily configure it to do what they
want, or just 'git pull --merge', or 'git fetch'+'git merge' (we
should make merge.defaulttoupstream=true as well).

> But neither is an easy sell, I would imagine.  It is not about
> passing me, but about not hurting users like kernel folks we
> accumulated over 7-8 years.

I've worked in the Linux kernel, and in my experience the vast vast
majority of kernel developers don't do merges; they send patches. It's
only the lieutenants that might do that, and although there are a lot,
they don't surpass the 200, and they most definitely know how to
configure Git to do what they need. And even then, most of them don't
do merges, but create a linear history for Linus to merge.

So the only one who does really rely on merges is Linus, I think he
would have no problems configuring Git.

It is also my experience that most people don't do 'git pull', because
it rarely does what one wants; 'upstream' is still too cumbersome for
most people.

> Also "rebase" of the branch you attempted to push out is sometimes a
> good solution (fixing "just a small change on 'master'" that was
> beaten by somebody else pushing first), but is a bad workaround (you
> had many changes on that branch, which would have been better if
> they were done on a topic branch, but you do not want to merge with
> the upstream because you worked on 'master') some other times, so I
> have this suspicion that 'pull.rebase' is not necessarily a good
> thing to encourage in the first place.

Too bad, that's what most people recommend; 'git fetch'+'git rebase'.
That's the only way newcomers can avoid the ugliness of 'upstream',
and avoid making atrocious merges.

It's silly that the people familiar with Git has to explain this to
each and every newcomer.

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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Junio C Hamano
John Keeping  writes:

> This isn't about "swap parents", it's about helping people realise that
> just "git pull" isn't necessarily the best thing for them to do, and
> that they may want --rebase.
>
> So I was asking if it would be sensible (possibly in Git 2.0) to make
> git-pull pass --ff-only to git-merge by default.

Unless your primary user base is those who use Git as a deployment
tool to always follow along the tip of some external repository
without doing anything on your own on the branch you run your "git
pull" on, defaulting it to --ff-only does not make much sense to me.

If the proposal were to make pull.rebase the default at a major
version bump and force all integrators and other people who are
happy with how "pull = fetch + merge" (not "fetch + rebase") works
to say "pull.rebase = false" in their configuration, I think I can
see why some people may think it makes sense, though.

But neither is an easy sell, I would imagine.  It is not about
passing me, but about not hurting users like kernel folks we
accumulated over 7-8 years.

Also "rebase" of the branch you attempted to push out is sometimes a
good solution (fixing "just a small change on 'master'" that was
beaten by somebody else pushing first), but is a bad workaround (you
had many changes on that branch, which would have been better if
they were done on a topic branch, but you do not want to merge with
the upstream because you worked on 'master') some other times, so I
have this suspicion that 'pull.rebase' is not necessarily a good
thing to encourage in the first place.
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Felipe Contreras
On Thu, May 23, 2013 at 4:55 PM, John Keeping  wrote:

> So I was asking if it would be sensible (possibly in Git 2.0) to make
> git-pull pass --ff-only to git-merge by default.

Definitely yes.

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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread John Keeping
On Thu, May 23, 2013 at 02:01:39PM -0700, Junio C Hamano wrote:
> John Keeping  writes:
> 
> > I have to wonder how often "git pull" with no arguments actually does
> > what users really want (even if they don't know it!) when it doesn't
> > result in a fast-forward (and pull.rebase isn't configured).
> 
> If you are in a totally centralized shared repository mindset
> without using topic branch workflow, --first-parent would not help
> you.  In your history the second parent is more likely to be the
> mainline.
> 
> So for them "git pull" that either fast-forward when it can, or
> makes a merge that records the then-current state of the central
> shared repository, is perfectly sensible.  They will view gitk and
> see all the changes, "git shortlog" and "git log --no-merges" will
> give them what they expect.

Yes, but for people used to a cleaner history it's confusing to see the
mainline branch and one small change the wrong way round.  When I see
people doing this, it's normally something like:

... do some work for several hours...
git commit -a
git push
# fails because it's not a fast forward
git pull
git push

In this scenario, just adding --rebase to "git pull" actually results in
a much more sensible history.

> > Hence my suggestion to error when "git pull" doesn't result in a
> > fast-forward and no branch name is specified.  We could give some advice
> > like:
> >
> > Your local changes are not included in the local branch and you
> > haven't told Git how to preserve them.
> >
> > If you want to rebase your changes onto the modified upstream
> > branch, run:
> >
> > git pull --rebase
> 
> I can parse the first paragraph above, but cannot make much sense
> out of it.  Unless you are talking about local changes that are not
> committed yet, that is.  But in that case I fail to see what it has
> to do with the current discussion, or suggestion to use rebase.

This isn't about "swap parents", it's about helping people realise that
just "git pull" isn't necessarily the best thing for them to do, and
that they may want --rebase.

So I was asking if it would be sensible (possibly in Git 2.0) to make
git-pull pass --ff-only to git-merge by default.
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Junio C Hamano
John Keeping  writes:

> I have to wonder how often "git pull" with no arguments actually does
> what users really want (even if they don't know it!) when it doesn't
> result in a fast-forward (and pull.rebase isn't configured).

If you are in a totally centralized shared repository mindset
without using topic branch workflow, --first-parent would not help
you.  In your history the second parent is more likely to be the
mainline.

So for them "git pull" that either fast-forward when it can, or
makes a merge that records the then-current state of the central
shared repository, is perfectly sensible.  They will view gitk and
see all the changes, "git shortlog" and "git log --no-merges" will
give them what they expect.

> Hence my suggestion to error when "git pull" doesn't result in a
> fast-forward and no branch name is specified.  We could give some advice
> like:
>
> Your local changes are not included in the local branch and you
> haven't told Git how to preserve them.
>
> If you want to rebase your changes onto the modified upstream
> branch, run:
>
> git pull --rebase

I can parse the first paragraph above, but cannot make much sense
out of it.  Unless you are talking about local changes that are not
committed yet, that is.  But in that case I fail to see what it has
to do with the current discussion, or suggestion to use rebase.

>> But people need to realize that it is not solving the other half, a
>> more fundamental problem some people have in their workflow.
>
> Yes, but some users don't realise that their workflow is broken, and
> perhaps we can nudge them in the right direction.

I actually avoided mentioning that deliberately, because I think the
"flip the head when merging" encourages people to (1) work directly
on 'master' and (2) pull too often when they shouldn't.

That is detrimental if your goal is to nudge them in the right
direction.
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Andreas Krey
On Thu, 23 May 2013 11:06:57 +, Andreas Krey wrote:
...
> ...
> > Don't do that, then.

Ouch, you're right. The problem is not actually in the
pull; only the *last* pull into a feature branch that
then get pushed back ff to master needs to be reversed.

And at that time you don't know it's the last one
-> swap parents before the push if necessary.

Andreas

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread John Keeping
On Thu, May 23, 2013 at 09:01:15AM -0700, Junio C Hamano wrote:
> John Keeping  writes:
> 
> > I've been annoyed by this at $DAYJOB recently.  A lot of people seem to
> > blindly "git pull" without much thought about how the history is ending
> > up and what they actually want to do.
> 
> I think these two are essentially the same thing, and having an
> option to flip the heads of a merge only solves a half of the
> problem.
> 
> A merge that shows everybody else's work merged into your history
> means you are the integrator, the keeper of the main history.  And
> the first-parent view of the history is useful only when the keeper
> of the main history takes good care of the main history.
> 
> When you are using a "central shared repository" workflow, if you
> had and used an option to flip the heads of a merge to record what
> you have done so far as a side branch of what everybody else did to
> do the merge, or if you rebased your work on top of what everybody
> else did, the first-parent view would make a bit more sense than
> what you currently get.  At least, everybody else's work will not
> appear as a side branch that does 47 unrelated things, and your work
> will appear as a side branch.  That is a big plus.
> 
> But the other half of the problem still remains, i.e. "what they
> actually want to do".  People tend to do too many "pull" when their
> work is not ready, only to "catch up", and that is the real problem.
...
> One obvious way to solve it is to use a topic branch workflow (the
> first picture above; 'x's are built not on local 'master'), and you
> do a "git pull" from the shared repository while you are on your
> 'master', which is free of your 'x's until that 6-commit series is
> complete and ready.  Then you locally merge that topic branch and
> push it back for everybody to see, which will give you the first
> picture in this message.  Incidentally, this does not need the "flip
> the heads" option.

Yes, I don't think this is as much of a problem when using a topic
branch workflow, because it's clear what the history should look like
and users are expected to get it right.

Where I see this is when people are aiming for a linear history but
don't get that because with "git pull" to catch up they end up with
these backwards merges.  In these cases, I think what users really want
is "git pull --rebase".

I have to wonder how often "git pull" with no arguments actually does
what users really want (even if they don't know it!) when it doesn't
result in a fast-forward (and pull.rebase isn't configured).

Hence my suggestion to error when "git pull" doesn't result in a
fast-forward and no branch name is specified.  We could give some advice
like:

Your local changes are not included in the local branch and you
haven't told Git how to preserve them.

If you want to rebase your changes onto the modified upstream
branch, run:

git pull --rebase

> Solving half a problem is better than solving no problem, and
> especially because not all changes need to be multi-commit series
> but can be done directly, perfectly and fully on the local 'master'
> (i.e. 2+3+1=6 split would not happen for such changes).  For these
> reasons, I personally am not strongly opposed to a "flip the heads"
> option, if implemented cleanly.
> 
> But people need to realize that it is not solving the other half, a
> more fundamental problem some people have in their workflow.

Yes, but some users don't realise that their workflow is broken, and
perhaps we can nudge them in the right direction.
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Junio C Hamano
John Keeping  writes:

> I've been annoyed by this at $DAYJOB recently.  A lot of people seem to
> blindly "git pull" without much thought about how the history is ending
> up and what they actually want to do.

I think these two are essentially the same thing, and having an
option to flip the heads of a merge only solves a half of the
problem.

A merge that shows everybody else's work merged into your history
means you are the integrator, the keeper of the main history.  And
the first-parent view of the history is useful only when the keeper
of the main history takes good care of the main history.

When you are using a "central shared repository" workflow, if you
had and used an option to flip the heads of a merge to record what
you have done so far as a side branch of what everybody else did to
do the merge, or if you rebased your work on top of what everybody
else did, the first-parent view would make a bit more sense than
what you currently get.  At least, everybody else's work will not
appear as a side branch that does 47 unrelated things, and your work
will appear as a side branch.  That is a big plus.

But the other half of the problem still remains, i.e. "what they
actually want to do".  People tend to do too many "pull" when their
work is not ready, only to "catch up", and that is the real problem.

Instead of having a nice "these six commits marked as 'x' were done
on a branch forked some time ago, to address only this one issue and
to address it fully" history that explains how these commits were
related and these commits are the full solution to a single issue:

  x---x---x---x---x---x
 / \
 ---o---o---o---o---o---o---M---o---o---...

they end up with something like this, even with the "flip the heads
of a merge" option, by pulling too often:

  x---x   x---x---x   x
 / \ / \ / \
 ---o---o---M---o---o---M---M---o---o---...

The result fragments otherwise a logical and clean "single strand of
pearls to fully address the issue, consisting of 6 commits", into
separate and seemingly unrelated pieces.

Imagine that other people are working the same way, and the commits
marked with 'o' are merges of side branches they add their half-way
work to the main history similar to what happened in the second
illustration above.  You would get this history:

  x---x   x---x---x   x
 / \ / \ / \
 ---o---o---M---o---M---M---M---o---o---...
 \ /
  y---y 

Nothing, other than the labels I used in the picture, ties these
'x's together while differentiating them from 'y's, so you lost an
important information.  Unless people stop doing that too many
"pull"s that are used only to "catch up", even with the "flip the
heads of a merge" option, you will not get a history that yields a
good first-parent view.

That gets back to what I said in the second paragraph of this
message.  When you "pull" from the central shared repository, with
the "flip the heads of a merge" option, you are acting as the keeper
of the main history at that point, and you are responsible for
taking good care of it.  If you make a 2+3+1=6 mess as depicted in
the last illustration above, you are failing to do so.

One obvious way to solve it is to use a topic branch workflow (the
first picture above; 'x's are built not on local 'master'), and you
do a "git pull" from the shared repository while you are on your
'master', which is free of your 'x's until that 6-commit series is
complete and ready.  Then you locally merge that topic branch and
push it back for everybody to see, which will give you the first
picture in this message.  Incidentally, this does not need the "flip
the heads" option.

Solving half a problem is better than solving no problem, and
especially because not all changes need to be multi-commit series
but can be done directly, perfectly and fully on the local 'master'
(i.e. 2+3+1=6 split would not happen for such changes).  For these
reasons, I personally am not strongly opposed to a "flip the heads"
option, if implemented cleanly.

But people need to realize that it is not solving the other half, a
more fundamental problem some people have in their workflow.
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Andreas Krey
On Thu, 23 May 2013 06:34:38 +, Felipe Contreras wrote:
...
> I don't understand; gitk already shows the first parent starting from
> the bottom, and the merge commits arrive from the right side. What am
> I missing?

That this isn't (consistently) the case in complicated situations.
I'll need to make a picture (as in png).

Andreas

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From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Felipe Contreras
On Wed, May 22, 2013 at 6:50 AM, Andreas Krey  wrote:
> Hi everyone,
>
> I'm just looking into better displays of the commit graph (as
> displayed with gitk, smartgit, fisheye) - they tend to quickly
> dissolve into a heap of spaghetti.
>
> We had the idea that treating the first parent specially would
> have some advantage here - including graphically indicating which
> one of the parents of a commit is the first parent. (For instance,
> by letting that line leave the commit node at the top/bottom,
> and the other(s) to the side.)

I don't understand; gitk already shows the first parent starting from
the bottom, and the merge commits arrive from the right side. What am
I missing?

-- 
Felipe Contreras
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread John Keeping
On Thu, May 23, 2013 at 12:29:59PM +0200, Andreas Krey wrote:
> On Thu, 23 May 2013 05:48:38 +, John Szakmeister wrote:
> ...
> > This is a feature of `git pull` that I really despise.  I really wish
> > `git pull` treated the remote as the first parent in its merge
> > operation.
> 
> I'd actually only like it that way when pulling from
> the tracking branch, not for any pull.

I'll add my voice to the "annoyed by this" pile ;-)

I've been annoyed by this at $DAYJOB recently.  A lot of people seem to
blindly "git pull" without much thought about how the history is ending
up and what they actually want to do.

I wonder if it would make sense for "git pull" (with no arguments) to
pass "--ff-only" to git-merge, allowing this to be overridden with
--rebase and --merge (which doesn't currently exist).  With some
suitable advice output we could hopefully educate users about how to
shape their history.
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Andreas Krey
On Thu, 23 May 2013 05:48:38 +, John Szakmeister wrote:
...
> This is a feature of `git pull` that I really despise.  I really wish
> `git pull` treated the remote as the first parent in its merge
> operation.

I'd actually only like it that way when pulling from
the tracking branch, not for any pull.

Andreas

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Jeremy Rosen

- Mail original -
> On Thu, May 23, 2013 at 5:06 AM, Andreas Krey  wrote:
> [snip]
> > ...
> >> Don't do that, then.
> >
> > :-) Problem is, in this case 'I' expands to about
> > 1<<7 people I need to educate on this.
> 
> This is a feature of `git pull` that I really despise.  I really wish
> `git pull` treated the remote as the first parent in its merge
> operation.
> 

seconded...

github's network pages (which display the commit graph of projects) seems to 
follow the "first parent at the top" rule and the pull merges are standing out 
as "wrong" because of that...
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread John Szakmeister
On Thu, May 23, 2013 at 5:06 AM, Andreas Krey  wrote:
[snip]
> ...
>> Don't do that, then.
>
> :-) Problem is, in this case 'I' expands to about
> 1<<7 people I need to educate on this.

This is a feature of `git pull` that I really despise.  I really wish
`git pull` treated the remote as the first parent in its merge
operation.

-John
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Re: first parent, commit graph layout, and pull merge direction

2013-05-23 Thread Andreas Krey
On Wed, 22 May 2013 11:07:07 +, Junio C Hamano wrote:
...
> If you have a four-commit segment in your commit ancestry graph

I never had yet. :-(

> (time flows from left to right; turn your head 90-degrees to the
> right if you want a gitk representation):
> 
> ---A--X
> \/
> /\
> ---B--Y
> 
> where X and Y are both merges between A and B, having A as their
> first parent, how would you express such a graph with first-parent
> chain going a straight line?

Of course there are multiple possible straight lines and how it looks
depends on the order I use the existing heads to fish them out. (That
is, when the straight lines join, I need to bend one of them.) Assuming
I take the one where X is on, I expect a look like

-A---X-
  \  |
   +- Y
  |  |
-B+--+

Branch heads that are reachable from other head are picked after those
that aren't reachable.

The point is to get the feature branches being displayed on separate
lanes (and thus visibly sticking out) and not being intermingled with
the longer-living branches.

...
> Don't do that, then.

:-) Problem is, in this case 'I' expands to about
1<<7 people I need to educate on this.

Andreas

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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Re: first parent, commit graph layout, and pull merge direction

2013-05-22 Thread Junio C Hamano
Andreas Krey  writes:

> A short trial showed that representing first parent chains as
> straight lines in the graph does actually improve understandability,
> as feature branches clearly stand out as separate lines even when
> they no longer carry a branch name.

If you have a four-commit segment in your commit ancestry graph
(time flows from left to right; turn your head 90-degrees to the
right if you want a gitk representation):

---A--X
\/
/\
---B--Y

where X and Y are both merges between A and B, having A as their
first parent, how would you express such a graph with first-parent
chain going a straight line?

> Also, there is an implication with 'git pull': You'd expect the
> master branch to be a first parent line, but when I do a small
> thing directly on master and need to pull before pushing back,
> then origin/master is merged into my branch, and thus my side
> branch becomes the first parent line.

Don't do that, then.
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first parent, commit graph layout, and pull merge direction

2013-05-22 Thread Andreas Krey
Hi everyone,

I'm just looking into better displays of the commit graph (as
displayed with gitk, smartgit, fisheye) - they tend to quickly
dissolve into a heap of spaghetti.

We had the idea that treating the first parent specially would
have some advantage here - including graphically indicating which
one of the parents of a commit is the first parent. (For instance,
by letting that line leave the commit node at the top/bottom,
and the other(s) to the side.)

A short trial showed that representing first parent chains as
straight lines in the graph does actually improve understandability,
as feature branches clearly stand out as separate lines even when
they no longer carry a branch name.

Does any GUI already do that (treat first parent specially),
or does anybody think of doing such? I don't quite dare to
jump into the gitk code yet.

Also, there is an implication with 'git pull': You'd expect the
master branch to be a first parent line, but when I do a small
thing directly on master and need to pull before pushing back,
then origin/master is merged into my branch, and thus my side
branch becomes the first parent line.

So, feature discussion request: Invert the parent ordering
when doing git pull from upstream? Configurably so?

We actually thought about putting a restriction into our blessed
repo that it not only restricts to fast-forward pushed, but further
to only allow pushing new things that have the old branch head in
the first parent chain.

What do you think?

-- 
"Totally trivial. Famous last words."
From: Linus Torvalds 
Date: Fri, 22 Jan 2010 07:29:21 -0800
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