Re: [PATCH v18 1/7] branch: add --forked filter for --list mode

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Harald

On 24/06/2026 22:55, Harald Nordgren via GitGitGadget wrote:
> From: Harald Nordgren <haraldnordgren@gmail.com>
> 
> Add a --forked option to "git branch" list mode that lists only
> branches whose configured upstream matches <branch>. The argument
> can be a ref (e.g. "origin/main", "master"), a remote name like
> "origin" for the branch its origin/HEAD points at, or a shell glob
> (e.g. "origin/*"), and may be repeated to widen the filter.
> 
> It is an ordinary list filter, so it combines with the others:
> 
>      git branch --merged origin/main --forked 'origin/*'
> 
> lists branches forked from origin that are already merged into
> origin/main, and --no-merged inverts the question.
> 
> This is the building block for --delete-merged, which deletes the
> listed branches once they have landed on their upstream.

The implementation looks good, I've left a couple of small comments on 
the tests. One thought I had was whether we want a mode which recurses 
so that if the upstream of topic2 is topic1 which has an upstream of 
origin/main --forked=recurse origin/main would list topic1 and topic2. 
So long as we don't think that is a sensible default we can add it in 
the future if we want.


> diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
> index e7829c2c4b..3104c555f6 100755
> --- a/t/t3200-branch.sh
> +++ b/t/t3200-branch.sh
> @@ -1717,4 +1717,126 @@ test_expect_success 'errors if given a bad branch name' '
>   	test_cmp expect actual
>   '
>   
> +test_expect_success '--forked: setup' '
> +	test_create_repo forked-upstream &&
> +	(
> +		cd forked-upstream &&
> +		test_commit base &&
> +		git branch one base &&
> +		git branch two base
> +	) &&
> +
> +	test_create_repo forked-other &&
> +	(
> +		cd forked-other &&
> +		test_commit other-base &&
> +		git branch foreign other-base
> +	) &&
> +
> +	git clone forked-upstream forked &&
> +	(
> +		cd forked &&
> +		git remote add -f other ../forked-other &&
> +		git remote set-head origin one &&

This is a bit strange because it does not match HEAD in the remote 
repository but it is necessary for '--forked <remote> uses the branch 
<remote>/HEAD'. I wonder if that test could be written to use main 
instead but I guess this doesn't do any harm.

> +		git branch local-base &&
> +		git branch --track local-one origin/one &&
> +		git branch --track local-two origin/two &&
> +		git branch --track local-foreign other/foreign &&
> +		git branch --track local-onbase local-base &&
> +
> +		git checkout local-one &&
> +		test_commit --no-tag local-one-work local-one.t &&
> +		git checkout local-foreign &&
> +		test_commit --no-tag local-foreign-work local-foreign.t &&
> +		git checkout --detach

Why do we need a detached HEAD?

> [...]
> +test_expect_success '--forked composes with --no-merged' '
> +	test_when_finished "git -C forked checkout --detach" &&
> +	git -C forked checkout local-one &&
> +	test_commit -C forked local-only &&

The branch "local-one" already has a local commit so why do we need this?

> +	git -C forked branch --forked "origin/*" --no-merged origin/one \
> +		--format="%(refname:short)" >actual &&
> +	echo local-one >expect &&
> +	test_cmp expect actual
> +'
> +
> +test_expect_success '--forked rejects unknown branch/pattern' '
> +	test_must_fail git -C forked branch --forked nope 2>err &&
> +	test_grep "not a valid branch or pattern" err
> +'
> +
> +test_expect_success '--forked requires a value' '
> +	test_must_fail git -C forked branch --forked 2>err &&
> +	test_grep "requires a value" err
> +'

It is a bit odd to have these two tests in the middle of the ones that 
check the functionality works.

> +test_expect_success '--forked <remote> uses the branch <remote>/HEAD points at' '
> +	git -C forked branch --forked origin --format="%(refname:short)" >actual &&
> +	echo local-one >expect &&
> +	test_cmp expect actual
> +'
> +
> +test_expect_success '--forked narrows a <pattern> argument' '
> +	git -C forked branch --forked "origin/*" "local-*" \
> +		--format="%(refname:short)" >actual &&
> +	cat >expect <<-\EOF &&
> +	local-one
> +	local-two
> +	EOF
> +	test_cmp expect actual
> +'
This is looking good

Thanks

Phillip