cherry picking several patches at once

cherry picking several patches at once

[Felipe Balbi]

Hi,

I wonder if it's possible to cherry several patches at once ?
Can't find anything on any docs, but something like:

$ git cherry-pick <commit_id_start>..<commit_id_end> -- \
	/path/to/directory

I want to do that because I keep patches to the musb driver (on linux
kernel) based on top of linus' mainline tree and on top of internal
tree.

The internal tree is outdated (not following mainline), but the musb
driver is basically in sync, so cherry picking works, but it's a bit
painful when I have to pick patches from community and manually
cherry-pick to the other branch based on my internal tree.

If there's a way (besides git rebase --onto) to do that I would very
much like to know.

Another thing that would be nice to have, is to pass the HEAD to which
we want to cherry-pick, so we can cherry-pick to not-checked-out
branches. Something like:

$ git cherry-pick <commit_id> <my_branch_name>

and combining both, of course:

$ git cherry-pick <commit_id_start>..<commit_id_end> \
	<my_branch_name> -- /path/to/directory

-- 
balbi

Re: cherry picking several patches at once

[Felipe Contreras]

Heippa,

On Thu, Jan 21, 2010 at 6:11 PM, Felipe Balbi <me@felipebalbi.com> wrote:
> I wonder if it's possible to cherry several patches at once ?
> Can't find anything on any docs, but something like:
>
> $ git cherry-pick <commit_id_start>..<commit_id_end> -- \
>        /path/to/directory
>
> I want to do that because I keep patches to the musb driver (on linux
> kernel) based on top of linus' mainline tree and on top of internal
> tree.
>
> The internal tree is outdated (not following mainline), but the musb
> driver is basically in sync, so cherry picking works, but it's a bit
> painful when I have to pick patches from community and manually
> cherry-pick to the other branch based on my internal tree.
>
> If there's a way (besides git rebase --onto) to do that I would very
> much like to know.

Have you tried something like:
git format-patch old-base --full-diff -- /path
git am -3 *.patch

> Another thing that would be nice to have, is to pass the HEAD to which
> we want to cherry-pick, so we can cherry-pick to not-checked-out
> branches.

I think that would not be possible because of the challenges when
dealing with conflicts.

Cheers.

-- 
Felipe Contreras

Re: cherry picking several patches at once

[Marc Weber]

Hi,

I like both ideas. I fact I had both my self.
Cherry-picking a range can be implemented using a simple shell script.
So that is not that important.

> I think that would not be possible because of the challenges when
> dealing with conflicts.
If cherry-picking to a not checkout branch causes conflicts it could be
rejected. It's that simple.

The use case is: You have many topic-branches. Of course you develop on
the big temporary merge. However you want to push your changes to the
topic branches. You may be working on multiple topics at the same time.
Some of the topics may quick hacks to make a porject work on your system
such as patching shebang lines, change PHP require lines etc.

Currently you have to
git checkout topic1; git cherry-pick big-merge
git checkout topic2; git cherry-pick big-merge~2
git checkout big-merge

compare this to

git cherry-push HEAD    topic1
git cherry-push HEAD~2  topic2

not much typing.

Very often there are no conflicts and you know that there are none.

If you have conflicts you can still fallback going the slow way.
Maybe the command could behave this way:

git cherry-push-checkout-on-failure hash other-branch

I'd be very happy about such a git cherry-push-checkout-on-failure
command. I'm not sure whether the command should be renamed. I did so
for fun.

Marc Weber

Re: cherry picking several patches at once

[Sverre Rabbelier]

Heya,

On Sat, Jan 23, 2010 at 01:24, Marc Weber <marco-oweber@gmx.de> wrote:
> git cherry-push-checkout-on-failure hash other-branch

Heh, I could use that exact command myself, as I use the exact
workflow you described :).

-- 
Cheers,

Sverre Rabbelier

Re: cherry picking several patches at once

[Felipe Balbi]

Hi,

On Sat, 2010-01-23 at 01:57 +0200, Felipe Contreras wrote:
> Have you tried something like:
> git format-patch old-base --full-diff -- /path
> git am -3 *.patch

yes, sure that can be done, but the idea is to avoid having
format-patch, switch branches and git am those patches ;-)

> I think that would not be possible because of the challenges when
> dealing with conflicts.

there shouldn't be any. I have the same driver internally and publicly
and would be cherry-picking only the patches for that particular driver.

-- 
balbi

Re: cherry picking several patches at once

[Felipe Contreras]

On Sun, Jan 24, 2010 at 12:52 PM, Felipe Balbi <me@felipebalbi.com> wrote:
> On Sat, 2010-01-23 at 01:57 +0200, Felipe Contreras wrote:
>> Have you tried something like:
>> git format-patch old-base --full-diff -- /path
>> git am -3 *.patch
>
> yes, sure that can be done, but the idea is to avoid having
> format-patch, switch branches and git am those patches ;-)

When you do a 'git rebase' you are also doing a format-patch/am, but
that happens inside the script; you can write a script that does what
you want in a way that you wouldn't notice it: save the old branch,
git stash, switch to new branch, generate the patches, apply the
patches, switch back to the old branch, git stash pop.

>> I think that would not be possible because of the challenges when
>> dealing with conflicts.
>
> there shouldn't be any. I have the same driver internally and publicly
> and would be cherry-picking only the patches for that particular driver.

Ok, in that case we would just need a cherry-pick that can commit to a
separate branch, however I don't think git internals allow that kind
of thing.

-- 
Felipe Contreras

Re: cherry picking several patches at once

[Marc Weber]

> Ok, in that case we would just need a cherry-pick that can commit to a
> separate branch, however I don't think git internals allow that kind
> of thing.

Which is the best way to implement this git-cherry-push command?

# naive implementation (BASH function):

gitCherryPush(){
  # start a subshell so that failures don't quit your shell because of
  # set -e
  (
  set -e
  local branch=$(cat .git/HEAD |  sed 's@ref: refs/heads/\(.*\)@\1@')
  local otherBranch=$1; shift
  commits="$(
    for range in "$@"; do
      local HAS_DOTS=${range%%*..*}
      # add -1 if commit is not a range
      git rev-list --reverse ${HAS_DOTS:+-1} "$range"
    done
  )"

  echo "checking out other branch"
  git checkout "$otherBranch"
  echo "$commits" | while read c; do
    git cherry-pick "$c" || {
      echo "cherry-picking $c failed. fix it, exit 1 to abort. Starting subshell now"
      $SHELL || [ "$?" != 1] || return
    }
  done
  echo "checking out original branch $branch"
  git checkout $branch
  )
}

zsh completion:

compdef _gitCherryPush gitCherryPush
_gitCherryPush(){
  typeset -A opt_args
  _arguments -S \
   ':branch to which to move commit range:__git_branch_names' \
   ':branch to which to move commit range:__git_commit_ranges2'
}

Example usage (push last 5 commits)
gitCherryPush branch-to-push-to HEAD~4 HEAD~4..HEAD

Can I checkout the other branch without touching the working copy? I
don't think so because cherry-pick will fail operating if working
directory is not clean, correct?

Is something like this worth comitting to the main repo?

Marc Weber