Subject: Re: [PATCH v3 1/1] range-diff: treat notes like `log`

From: Junio C Hamano <[email-masked]>
Date: Mon, 11 Sep 2023 12:55:26 -0700

Kristoffer Haugsbakk <[email-masked]> writes:

>> To fix this explicitly set the output format of the internally executed
>> `git log` with `--pretty=medium`. Because that cancels `--notes`, add
>> explicitly `--notes` at the end.
>
> § Authors
>
> • Fix by Johannes
> • Tests by Kristoffer
>
> † 1: See e.g. 66b2ed09c2 (Fix "log" family not to be too agressive about
>     showing notes, 2010-01-20).
>
> Co-authored-by: Johannes Schindelin <[email-masked]>
> Signed-off-by: Kristoffer Haugsbakk <[email-masked]>
> ---

OK, Dscho, does this round look acceptable to you?

It feels UGLY to iterate over args _without_ actually parsing them,
at least to me.  Such a non-parsing look breaks at least in two ways
over time. (1) a mechanism may be introduced laster, similar to
"--", that allows other_arg->v[] array to mark "here is where the
dashed options end".  Now the existing loop keeps reading to the end
and finds "--notes" that is not a dashed option but is part of the
normal command line arguments in "other arg".  (2) Among the dashed
options passed in the other_arg->v[], there may be an option that
takes a string value, and a value that happens to be "--notes" is
mistaken as asking for "notes" (iow "git log -G --notes" is looking
for commits with changes that contain "double dash followed by en oh
tee ee es").

I think "git range-diff -G --notes" (or "-S --notes") shows that
this new non-parsing loop is already broken.  It looks for a change
that has "--notes" correctly, but at the same time, triggers that
"ah, we have an explicit --notes so drop the implicit_notes_arg
flag" logic.

>  range-diff.c          | 13 +++++++++++--
>  t/t3206-range-diff.sh | 28 ++++++++++++++++++++++++++++
>  2 files changed, 39 insertions(+), 2 deletions(-)
>
> diff --git a/range-diff.c b/range-diff.c
> index 2e86063491..fbb81a92cc 100644
> --- a/range-diff.c
> +++ b/range-diff.c
> @@ -41,12 +41,20 @@ static int read_patches(const char *range, struct string_list *list,
>  	struct child_process cp = CHILD_PROCESS_INIT;
>  	struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
>  	struct patch_util *util = NULL;
> -	int in_header = 1;
> +	int i, implicit_notes_arg = 1, in_header = 1;
>  	char *line, *current_filename = NULL;
>  	ssize_t len;
>  	size_t size;
>  	int ret = -1;
>  
> +	for (i = 0; other_arg && i < other_arg->nr; i++)
> +		if (!strcmp(other_arg->v[i], "--notes") ||
> +		    starts_with(other_arg->v[i], "--notes=") ||
> +		    !strcmp(other_arg->v[i], "--no-notes")) {
> +			implicit_notes_arg = 0;
> +			break;
> +		}
> +
>  	strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
>  		     "--reverse", "--date-order", "--decorate=no",
>  		     "--no-prefix", "--submodule=short",
> @@ -60,8 +68,9 @@ static int read_patches(const char *range, struct string_list *list,
>  		     "--output-indicator-context=#",
>  		     "--no-abbrev-commit",
>  		     "--pretty=medium",
> -		     "--notes",
>  		     NULL);
> +	if (implicit_notes_arg)
> +		     strvec_push(&cp.args, "--notes");
>  	strvec_push(&cp.args, range);
>  	if (other_arg)
>  		strvec_pushv(&cp.args, other_arg->v);
> diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
> index b5f4d6a653..b33afa1c6a 100755
> --- a/t/t3206-range-diff.sh
> +++ b/t/t3206-range-diff.sh
> @@ -662,6 +662,20 @@ test_expect_success 'range-diff with multiple --notes' '
>  	test_cmp expect actual
>  '
>  
> +# `range-diff` should act like `log` with regards to notes
> +test_expect_success 'range-diff with --notes=custom does not show default notes' '
> +	git notes add -m "topic note" topic &&
> +	git notes add -m "unmodified note" unmodified &&
> +	git notes --ref=custom add -m "topic note" topic &&
> +	git notes --ref=custom add -m "unmodified note" unmodified &&
> +	test_when_finished git notes remove topic unmodified &&
> +	test_when_finished git notes --ref=custom remove topic unmodified &&
> +	git range-diff --notes=custom main..topic main..unmodified \
> +		>actual &&
> +	! grep "## Notes ##" actual &&
> +	grep "## Notes (custom) ##" actual
> +'
> +
>  test_expect_success 'format-patch --range-diff does not compare notes by default' '
>  	git notes add -m "topic note" topic &&
>  	git notes add -m "unmodified note" unmodified &&
> @@ -679,6 +693,20 @@ test_expect_success 'format-patch --range-diff does not compare notes by default
>  	! grep "note" 0000-*
>  '
>  
> +test_expect_success 'format-patch --notes=custom --range-diff only compares custom notes' '
> +	git notes add -m "topic note" topic &&
> +	git notes --ref=custom add -m "topic note (custom)" topic &&
> +	git notes add -m "unmodified note" unmodified &&
> +	git notes --ref=custom add -m "unmodified note (custom)" unmodified &&
> +	test_when_finished git notes remove topic unmodified &&
> +	test_when_finished git notes --ref=custom remove topic unmodified &&
> +	git format-patch --notes=custom --cover-letter --range-diff=$prev \
> +		main..unmodified >actual &&
> +	test_when_finished "rm 000?-*" &&
> +	grep "## Notes (custom) ##" 0000-* &&
> +	! grep "## Notes ##" 0000-*
> +'
> +
>  test_expect_success 'format-patch --range-diff with --no-notes' '
>  	git notes add -m "topic note" topic &&
>  	git notes add -m "unmodified note" unmodified &&