From: Junio C Hamano <hidden> Date: 2016-06-15 22:48:35
Sverre Rabbelier [off-list ref] writes:
On Fri, Apr 9, 2010 at 20:49, Eugene Sajine [off-list ref] wrote:
quoted
But, in “git rebase –onto master next topic” the meaning of the “next
topic” parameters is different: as I understand, it actually specifies
a range of commits from next to topic, because –onto changes the way
the whole command is working, but it is not clarified in help. Is that
correct understanding?
I've never been able to remember how rebase --onto works, perhaps if
we actually let users specify a range it would be more intuitive?
$ git rebase next..topic master
Hmm, re*base* means "change the base to _this one_"; the above is more
like "replay these on master", which is often a useful operation but is
different.
Suppose other people have worked on the project and made their pushes
since you started working on your changes:
o---o master
/
---o---o---o---o origin
"git rebase origin" asks "I know my current work is based on a tad stale
state, and I'd prefer a linear history, so change the base to origin".
If the thing of whose base you want to change is not your "current work",
then you name that explicitly, i.e. "git rebase origin master" (i.e. the
second branch name defaults to HEAD as usual).
Onto is an optional feature that is primarily for correcting your earlier
mistakes. Notice in the above picture, other people doing parallel work
and pushing their changes out is part of the normal life of distributed
development; there is no mistake on your part involved.
But suppose you started building bugfixes in a topic forked from origin,
but after that you realize they should be based on origin/maint:
X---Y fixes
/
o---o---o---o---o origin
/
---o---o---o origin/maint
You could have made fixes branch that houses X and Y on origin/maint (and
later merge that to master to be pushed to origin), but you did not have
perfect foresight. You do not obviously want to change the base of whole
'fixes' branch to 'origin/maint', as that will pull in changes in origin
that are not related to your fixes.
You would want to rebase 'fixes' branch (whose fork point can be specified
with 'origin') but not on top of 'origin', but on 'origin/maint'. Hence
instead of running "git rebase origin" to produce
X'--Y' fixes
/
o---o---o---o---o origin
/
---o---o---o origin/maint
You would say "git rebase --onto origin/maint origin" to transplant X' and
Y' as if you started working from 'origin/maint':
o---o---o---o---o origin
/
---o---o---o origin/maint
\
X'--Y' fixes
If you _had_ your "replay" command, the workflow for this would be:
$ git checkout -b maint-fixes origin/maint
$ git replay origin..fixes
Before somebody else makes useless noises, "cherry-pick" could be a good
command in the existing UI set to do that kind of thing.
Heya,
On Fri, Apr 9, 2010 at 23:11, Junio C Hamano [off-list ref] wrote:
Hmm, re*base* means "change the base to _this one_"; the above is more
like "replay these on master", which is often a useful operation but is
different.
Yes, I guess that's true.
If you _had_ your "replay" command, the workflow for this would be:
$ git checkout -b maint-fixes origin/maint
$ git replay origin..fixes
True again.
Before somebody else makes useless noises, "cherry-pick" could be a good
command in the existing UI set to do that kind of thing.
I still think the UI for --onto is awkward. At the very least it should be:
git rebase --fork-at=origin origin/maint fixes
Or something like that. Since currently you suddenly have to specify
an argument to --onto that was previously positional. Does that make
sense?
Case 1:
git rebase origin fixes
git rebase <new_base> <tip>
Case 2:
git rebase --onto origin/maint origin fixes
git rebase --onto=<new_base> <fork_point> <tip>
I know that in the --onto case <new_base> is not an argument to
--onto, but that's what it looks/feels like. Said differently, it's
just _really weird_ that a new argument (for a different mode) shows
up between two other arguments. It should either be at the beginning,
or at the end, but in the middle is just awkward, no?
So another solution might be to change the position of the
<fork_point> in the --onto case.
--
Cheers,
Sverre Rabbelier
On Fri, Apr 9, 2010 at 5:23 PM, Sverre Rabbelier [off-list ref] wrote:
Heya,
On Fri, Apr 9, 2010 at 23:11, Junio C Hamano [off-list ref] wrote:
quoted
Hmm, re*base* means "change the base to _this one_"; the above is more
like "replay these on master", which is often a useful operation but is
different.
Yes, I guess that's true.
I'm a bit confused. Isn't the rebase actually replaying the commits
one by one starting from new base instead of old one?
I believe it does apply diffs one by one, else there would be no
conflicts during rebase whatsoever.
Secondly, git complains about range not specified if you will try to
execute something like
git rebase --onto master topic
when topic is not direct descendant of master.
Git will say "not a range".
So, That's why i make a conclusion that the real meaning of
git rebase --onto master next topic
is very close if not exactly matching the
git rebase --onto master next..topic
quoted
If you _had_ your "replay" command, the workflow for this would be:
$ git checkout -b maint-fixes origin/maint
$ git replay origin..fixes
True again.
Yep therefore the interface
quoted
Before somebody else makes useless noises, "cherry-pick" could be a good
command in the existing UI set to do that kind of thing.
I still think the UI for --onto is awkward. At the very least it should be:
git rebase --fork-at=origin origin/maint fixes
Or something like that. Since currently you suddenly have to specify
an argument to --onto that was previously positional. Does that make
sense?
Case 1:
git rebase origin fixes
git rebase <new_base> <tip>
Case 2:
git rebase --onto origin/maint origin fixes
git rebase --onto=<new_base> <fork_point> <tip>
I know that in the --onto case <new_base> is not an argument to
--onto, but that's what it looks/feels like.
How is that possible that it is not an argument to --onto???
from docs:
SYNOPSIS
git rebase [-i | --interactive] [options] [--onto <newbase>]
<upstream> [<branch>]
git rebase [-i | --interactive] [options] --onto <newbase>
--root [<branch>]
git rebase --continue | --skip | --abort
When i'm executing
git rebase --onto master next topic
master is exactly the new base, new fork point for topic, which was
previously forked from next!
Said differently, it's
just _really weird_ that a new argument (for a different mode) shows
up between two other arguments. It should either be at the beginning,
or at the end, but in the middle is just awkward, no?
So another solution might be to change the position of the
<fork_point> in the --onto case.
--
Cheers,
Sverre Rabbelier