Re: [PATCH v2 1/5] diff-merges: introduce --diff-merges=on

> Introduce the notion of default diff format for merges, and the option
> "on" to select it. The default format is "separate" and can't yet
> be changed, so effectively "on" is just a synonym for "separate"
> for now. Add corresponding test to t4013.
>
> This is in preparation for introducing log.diffMerges configuration
> option that will let --diff-merges=on to be configured to any
> supported format.

> Signed-off-by: Sergey Organov <sorganov@gmail.com>
> ---
>  diff-merges.c           | 7 +++++++
>  t/t4013-diff-various.sh | 8 ++++++++
>  2 files changed, 15 insertions(+)
>
> diff --git a/diff-merges.c b/diff-merges.c
> index 146bb50316a6..ff227368bd46 100644
> --- a/diff-merges.c
> +++ b/diff-merges.c
> @@ -2,6 +2,11 @@
>  
>  #include "revision.h"
>  
> +typedef void (*diff_merges_setup_func_t)(struct rev_info *);
> +static void set_separate(struct rev_info *revs);
> +
> +static diff_merges_setup_func_t set_to_default = set_separate;
> +
>  static void suppress(struct rev_info *revs)
>  {
>  	revs->separate_merges = 0;
> @@ -66,6 +71,8 @@ static void set_diff_merges(struct rev_info *revs, const char *optarg)
>  		set_combined(revs);
>  	else if (!strcmp(optarg, "cc") || !strcmp(optarg, "dense-combined"))
>  		set_dense_combined(revs);
> +	else if (!strcmp(optarg, "on"))
> +		set_to_default(revs);
>  	else
>  		die(_("unknown value for --diff-merges: %s"), optarg);
>  
> diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
> index 6cca8b84a6bf..26a7b4d19d4d 100755
> --- a/t/t4013-diff-various.sh
> +++ b/t/t4013-diff-various.sh
> @@ -452,6 +452,14 @@ diff-tree --stat --compact-summary initial mode
>  diff-tree -R --stat --compact-summary initial mode
>  EOF
>  
> +test_expect_success 'log --diff-merges=on matches --diff-merges=separate' '
> +	git log -p --diff-merges=separate master >result &&
> +	process_diffs result >expected &&
> +	git log -p --diff-merges=on master >result &&
> +	process_diffs result >actual &&
> +	test_cmp expected actual
> +'
> +
>  test_expect_success 'log -S requires an argument' '
>  	test_must_fail git log -S
>  '