Re: "tla missing -s" equivalent with git/cogito

From: Petr Baudis <pasky@suse.cz>
Date: Jan 18, 2006, 18:55 UTC
Message-ID: <20060118185542.GT28365@pasky.or.cz>
In-Reply-To: <46a038f90601180956r69ba5dffl2106f697a6be4750@mail.gmail.com>

Dear diary, on Wed, Jan 18, 2006 at 06:56:38PM CET, I got a letter where Martin Langhoff <martin.langhoff@gmail.com> said that...

Show 16 quoted lines

> Andreas' response is good is you're into pure git. Let me add some
> cogito tricks ;-)
> 
> On 1/19/06, Belmar-Letelier <luis@itaapy.com> wrote:
> > arch-tla equivalent of
> >
> > $ cd project--luis--0.1
> > $ tla missing -sD paul@mail.com--public/project--paul--0.1
> 
>  $ cd project-luis
>  # only if have to do cg-branch-add the first time!
>  $ cg-branch-add paul http://server/git/project.git
>  $ cg-fetch paul
>  # show what paul has that we don't
>  $ cg-log -r master:paul
>  $ cg-diff -r master:paul

I usually do this as

	$ cg-log -m -r paul

which is shorter (and in some situations more accurately describes which commits are actually going to get merged).

But I believe that Belmar-Letelier might be happier with git-cherry, since he wants to do cherrypicking (and wrapping that in cg-log might not be bad idea).

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> > or I cherry pick only one of them (here patch-6) with
> >
> > $ tla replay  somefriend@mail.com--public/project--branchA--0.1--patch-6
> 
>   # export the patches paul has that we don't
>   $ mkdir .patchesfrompaul
>   $ git-format-patch --mbox --signoff -o .patchesfrompaul master paul
>   # review the contents of .patchesfrompaul and decide what patches you want
>   $ git-am -3 .patchesfrompaul/0006-fix-frob-invocation.txt

If you just want to pick one commit, it shouldn't be more difficult than

	$ cg-diff -p -r commitid | cg-patch
	$ cg-commit -c commitid

but I was actually thinking about wrapping this up to something like
cg-cherrypick or cg-pick. Perhaps I will just overload cg-patch, though
- I want to add support for autocommitting the patches there anyway.

> When you cherry pick patches, if the patch applies cleanly, the next
> time you do a merge from that branch it will be skipped automagically.
> If the patch needs serious editing, there's a good chance that git
> will try to apply it again.

No, it will not be skipped automagically - GIT really does not properly support merging of branch you've cherrypicked before. It might work, but that's just luck - very similar to the luck you might have when re-merging branches in CVS using the original merge base.

Imagine having branch with two patches 1 and 2. There is a file X:

Ppatch1:

	-a
	+b
	+c

Patch2:

	-b
	+a
	c

Resulting file:

	a
	c

Now, you've cherrypicked patch1, so your file is:

	b
	c

Now you want to merge the branch as a whole. Cherrypicking-aware VCS would just merge the patch2, but you are taking the whole diff:

	a
	+c

And you get a conflict instead of b\nc.

-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
Of the 3 great composers Mozart tells us what it's like to be human,
Beethoven tells us what it's like to be Beethoven and Bach tells us
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