Subject: Re: [PATCH v5] git-apply: allow simultaneous --cached and --3way options

From: Junio C Hamano <[email-masked]>
Date: Thu, 08 Apr 2021 06:33:05 -0700

Jerry Zhang <[email-masked]> writes:

>  Documentation/git-apply.txt |  6 +++--
>  apply.c                     |  9 ++++---
>  t/t4108-apply-threeway.sh   | 50 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 59 insertions(+), 6 deletions(-)

Nicely done.  Will queue.

Elijah, how does this round look to you?

> diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
> index 9144575299c264dd299b542b7b5948eef35f211c..aa1ae56a25e0428cabcfa2539900ef2a09abcb7c 100644
> --- a/Documentation/git-apply.txt
> +++ b/Documentation/git-apply.txt
> @@ -87,8 +87,10 @@ OPTIONS
>  	Attempt 3-way merge if the patch records the identity of blobs it is supposed
>  	to apply to and we have those blobs available locally, possibly leaving the
>  	conflict markers in the files in the working tree for the user to
> -	resolve.  This option implies the `--index` option, and is incompatible
> -	with the `--reject` and the `--cached` options.
> +	resolve.  This option implies the `--index` option unless the
> +	`--cached` option is used, and is incompatible with the `--reject` option.
> +	When used with the `--cached` option, any conflicts are left at higher stages
> +	in the cache.
>  
>  --build-fake-ancestor=<file>::
>  	Newer 'git diff' output has embedded 'index information'
> diff --git a/apply.c b/apply.c
> index 9bd4efcbced842d2c5c030a0f2178ddb36114600..dadab80ec967357b031657d4e3d0ae52fac11411 100644
> --- a/apply.c
> +++ b/apply.c
> @@ -133,8 +133,6 @@ int check_apply_state(struct apply_state *state, int force_apply)
>  
>  	if (state->apply_with_reject && state->threeway)
>  		return error(_("--reject and --3way cannot be used together."));
> -	if (state->cached && state->threeway)
> -		return error(_("--cached and --3way cannot be used together."));
>  	if (state->threeway) {
>  		if (is_not_gitdir)
>  			return error(_("--3way outside a repository"));
> @@ -4644,8 +4642,11 @@ static int write_out_results(struct apply_state *state, struct patch *list)
>  				fprintf(stderr, "U %s\n", item->string);
>  		}
>  		string_list_clear(&cpath, 0);
> -
> -		repo_rerere(state->repo, 0);
> +		/* Rerere relies on the partially merged result being in the working tree
> +		 * with conflict markers, but that isn't written with --cached.
> +		 */
> +		if (!state->cached)
> +			repo_rerere(state->repo, 0);
>  	}
>  
>  	return errs;
> diff --git a/t/t4108-apply-threeway.sh b/t/t4108-apply-threeway.sh
> index 9ff313f976422f9c12dc8032d14567b54cfe3765..65147efdea9a00e30d156e6f4d5d72a3987f230d 100755
> --- a/t/t4108-apply-threeway.sh
> +++ b/t/t4108-apply-threeway.sh
> @@ -180,4 +180,54 @@ test_expect_success 'apply -3 with ambiguous repeating file' '
>  	test_cmp expect one_two_repeat
>  '
>  
> +test_expect_success 'apply with --3way --cached clean apply' '
> +	# Merging side should be similar to applying this patch
> +	git diff ...side >P.diff &&
> +
> +	# The corresponding cleanly applied merge
> +	git reset --hard &&
> +	git checkout main~ &&
> +	git merge --no-commit side &&
> +	git ls-files -s >expect.ls &&
> +
> +	# should succeed
> +	git reset --hard &&
> +	git checkout main~ &&
> +	git apply --cached --3way P.diff &&
> +	git ls-files -s >actual.ls &&
> +	print_sanitized_conflicted_diff >actual.diff &&
> +
> +	# The cache should resemble the corresponding merge
> +	# (both files at stage #0)
> +	test_cmp expect.ls actual.ls &&
> +	# However the working directory should not change
> +	>expect.diff &&
> +	test_cmp expect.diff actual.diff
> +'
> +
> +test_expect_success 'apply with --3way --cached and conflicts' '
> +	# Merging side should be similar to applying this patch
> +	git diff ...side >P.diff &&
> +
> +	# The corresponding conflicted merge
> +	git reset --hard &&
> +	git checkout main^0 &&
> +	test_must_fail git merge --no-commit side &&
> +	git ls-files -s >expect.ls &&
> +
> +	# should fail to apply
> +	git reset --hard &&
> +	git checkout main^0 &&
> +	test_must_fail git apply --cached --3way P.diff &&
> +	git ls-files -s >actual.ls &&
> +	print_sanitized_conflicted_diff >actual.diff &&
> +
> +	# The cache should resemble the corresponding merge
> +	# (one file at stage #0, one file at stages #1 #2 #3)
> +	test_cmp expect.ls actual.ls &&
> +	# However the working directory should not change
> +	>expect.diff &&
> +	test_cmp expect.diff actual.diff
> +'
> +
>  test_done