Re: [PATCH 4/7] checkout: fix merge.conflictstyle handling

From: Phillip Wood <phillip.wood123@gmail.com>
To: Felipe Contreras <felipe.contreras@gmail.com>, git@vger.kernel.org
Cc: "David Aguilar" <davvid@gmail.com>,
	"Junio C Hamano" <gitster@pobox.com>,
	"Sergey Organov" <sorganov@gmail.com>,
	"Bagas Sanjaya" <bagasdotme@gmail.com>,
	"Elijah Newren" <newren@gmail.com>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Denton Liu" <liu.denton@gmail.com>
Subject: Re: [PATCH 4/7] checkout: fix merge.conflictstyle handling
Date: Thu, 10 Jun 2021 10:32:24 +0100	[thread overview]
Message-ID: <b4b9264d-1c17-1a62-f0ec-2791ab20adeb@gmail.com> (raw)
In-Reply-To: <20210609192842.696646-5-felipe.contreras@gmail.com>

On 09/06/2021 20:28, Felipe Contreras wrote:
> Currently both merge.conflictStyle and `git commit --merge
> --conflict=diff3` don't work together, since the former wrongly
> overrides the later.
> 
> The way merge configurations are handled is not correct.
> It should be possible to do git_config(merge_recursive_config, ...) just
> like we can with git_diff_basic_config and others.

It would be helpful to explain what the problem with 
merge_recursive_config() actually is rather than just saying "it should 
be possible ..."

> Therefore builtins like `git merge` can't call this function at the
> right time.
 >
> We shuffle the functions a little bit so at least merge_recursive_config
> doesn't call git_xmerge_config directly and thus override previous
> configurations.

Rather than papering of the problem, how difficult would it be to add a 
field to ll_merge_options and pass the conflict style with that rather 
than fiddling with the order that we set a global variable.

Does this change affect 'am/apply -3'? - Do they still read the config 
setting properly?

Best Wishes

Phillip

> Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
> ---
>   builtin/merge-recursive.c          |  3 +++
>   builtin/merge.c                    |  4 ++++
>   merge-recursive.c                  |  2 +-
>   sequencer.c                        |  5 +++++
>   t/t6440-config-conflict-markers.sh | 31 ++++++++++++++++++++++++++++++
>   5 files changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/builtin/merge-recursive.c b/builtin/merge-recursive.c
> index a4bfd8fc51..80f9279b4c 100644
> --- a/builtin/merge-recursive.c
> +++ b/builtin/merge-recursive.c
> @@ -4,6 +4,7 @@
>   #include "tag.h"
>   #include "merge-recursive.h"
>   #include "xdiff-interface.h"
> +#include "config.h"
>   
>   static const char builtin_merge_recursive_usage[] =
>   	"git %s <base>... -- <head> <remote> ...";
> @@ -30,6 +31,8 @@ int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
>   	char *better1, *better2;
>   	struct commit *result;
>   
> +	git_config(git_xmerge_config, NULL);
> +
>   	init_merge_options(&o, the_repository);
>   	if (argv[0] && ends_with(argv[0], "-subtree"))
>   		o.subtree_shift = "";
> diff --git a/builtin/merge.c b/builtin/merge.c
> index eddb8ae70d..7aa3dbb111 100644
> --- a/builtin/merge.c
> +++ b/builtin/merge.c
> @@ -43,6 +43,7 @@
>   #include "commit-reach.h"
>   #include "wt-status.h"
>   #include "commit-graph.h"
> +#include "xdiff-interface.h"
>   
>   #define DEFAULT_TWOHEAD (1<<0)
>   #define DEFAULT_OCTOPUS (1<<1)
> @@ -659,6 +660,9 @@ static int git_merge_config(const char *k, const char *v, void *cb)
>   	if (status)
>   		return status;
>   	status = git_gpg_config(k, v, NULL);
> +	if (status)
> +		return status;
> +	status = git_xmerge_config(k, v, NULL);
>   	if (status)
>   		return status;
>   	return git_diff_ui_config(k, v, cb);
> diff --git a/merge-recursive.c b/merge-recursive.c
> index d146bb116f..10e6e1e4d1 100644
> --- a/merge-recursive.c
> +++ b/merge-recursive.c
> @@ -3845,7 +3845,7 @@ static void merge_recursive_config(struct merge_options *opt)
>   		} /* avoid erroring on values from future versions of git */
>   		free(value);
>   	}
> -	git_config(git_xmerge_config, NULL);
> +	git_config(git_default_config, NULL);
>   }
>   
>   void init_merge_options(struct merge_options *opt,
> diff --git a/sequencer.c b/sequencer.c
> index 0bec01cf38..9e2bdca0f6 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -34,6 +34,7 @@
>   #include "commit-reach.h"
>   #include "rebase-interactive.h"
>   #include "reset.h"
> +#include "xdiff-interface.h"
>   
>   #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
>   
> @@ -224,6 +225,10 @@ static int git_sequencer_config(const char *k, const char *v, void *cb)
>   	if (status)
>   		return status;
>   
> +	status = git_xmerge_config(k, v, NULL);
> +	if (status)
> +		return status;
> +
>   	return git_diff_basic_config(k, v, NULL);
>   }
>   
> diff --git a/t/t6440-config-conflict-markers.sh b/t/t6440-config-conflict-markers.sh
> index 44f79ac91b..485ad0eee0 100755
> --- a/t/t6440-config-conflict-markers.sh
> +++ b/t/t6440-config-conflict-markers.sh
> @@ -89,4 +89,35 @@ test_expect_success 'notes' '
>   	)
>   '
>   
> +test_expect_success 'checkout' '
> +	test_create_repo checkout &&
> +	(
> +		test_commit checkout &&
> +
> +		fill a b c d e >content &&
> +		git add content &&
> +		git commit -m initial &&
> +
> +		git checkout -b simple master &&
> +		fill a c e >content &&
> +		git commit -a -m simple &&
> +
> +		fill b d >content &&
> +		git checkout --merge master &&
> +		! grep -E "\|+" content &&
> +
> +		git config merge.conflictstyle merge &&
> +
> +		git checkout -f simple &&
> +		fill b d >content &&
> +		git checkout --merge --conflict=diff3 master &&
> +		grep -E "\|+" content &&
> +
> +		git checkout -f simple &&
> +		fill b d >content &&
> +		git checkout --merge --conflict=merge master &&
> +		! grep -E "\|+" content
> +	)
> +'
> +
>   test_done
> 