Re: [PATCH v2 1/3] range-diff: treat notes like `log`

From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: Kristoffer Haugsbakk <code@khaugsbakk.name>
Cc: git@vger.kernel.org, Denton Liu <liu.denton@gmail.com>,
	Jeff King <peff@peff.net>
Subject: Re: [PATCH v2 1/3] range-diff: treat notes like `log`
Date: Sun, 3 Sep 2023 14:17:59 +0200 (CEST)	[thread overview]
Message-ID: <94b9535b-8c2a-eb8f-90fb-cd0f998ec57e@gmx.de> (raw)
In-Reply-To: <e9a59108311369d8197b9870a8810d5283ec124f.1693584310.git.code@khaugsbakk.name>

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Hi Kristoffer,

On Fri, 1 Sep 2023, Kristoffer Haugsbakk wrote:

> Currently, `range-diff` shows the default notes if no notes-related
> arguments are given. This is also how `log` behaves. But unlike
> `range-diff`, `log` does *not* show the default notes if
> `--notes=<custom>` are given. In other words, this:
>
>     git log --notes=custom
>
> is equivalent to this:
>
>     git log --no-notes --notes=custom
>
> While:
>
>     git range-diff --notes=custom
>
> acts like this:
>
>     git log --notes --notes-custom
>
> This can’t be how the user expects `range-diff` to behave given that the
> man page for `range diff` under `--[no-]notes[=<ref>]` says:
>
> > This flag is passed to the git log program (see git-log(1)) that
> > generates the patches.
>
> This behavior also affects `format-patch` since it uses `range-diff` for
> the cover letter. Unlike `log`, though, `format-patch` is not supposed
> to show the default notes if no notes-related arguments are given.[1]
> But this promise is broken when the range-diff happens to have something
> to say about the changes to the default notes, since that will be shown
> in the cover letter.

Very well explained.

The root cause for this is 8cf51561d1e (range-diff: fix a crash in parsing
git-log output, 2020-04-15) which added the `--notes` argument in
`read_patches()`' call. The commit message explains why this is needed:
the (necessary) `--pretty=medium` would turn off the notes, therefore
`--notes` had to be added to reinstate the original behavior (except, as
you pointed out, in the case `--notes=<ref>` was specified).

> Remedy this by co-opting the `--standard-notes` option which has been
> deprecated since ab18b2c0df[2] and which is currently only documented in
> `pretty-options`.

This sounds a bit less desirable, though, than passing the `--notes`
argument only as needed. This patch (on top of `notes-range-diff` in your
fork) lets the new test still pass while leaving `--standard-notes`
deprecated:

-- snipsnap --

diff --git a/Documentation/pretty-options.txt b/Documentation/pretty-options.txt
index 8c982609c99..dc685be363a 100644
--- a/Documentation/pretty-options.txt
+++ b/Documentation/pretty-options.txt
@@ -88,6 +88,7 @@ being displayed. Examples: "--notes=foo" will show only notes from
 	from "refs/notes/bar".

 --show-notes[=<ref>]::
+--[no-]standard-notes::
 	These options are deprecated. Use the above --notes/--no-notes
 	options instead.
 endif::git-rev-list[]
diff --git a/range-diff.c b/range-diff.c
index f070e4a4ceb..fbb81a92cc0 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",
-		     "--standard-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/revision.c b/revision.c
index 44a04004a70..2f4c53ea207 100644
--- a/revision.c
+++ b/revision.c
@@ -2495,13 +2495,9 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		disable_display_notes(&revs->notes_opt, &revs->show_notes);
 		revs->show_notes_given = 1;
 	} else if (!strcmp(arg, "--standard-notes")) {
-		disable_display_notes(&revs->notes_opt, &revs->show_notes);
-		revs->show_notes_given = 0;
-		enable_default_display_notes(&revs->notes_opt,
-					     &revs->show_notes);
-		revs->notes_opt.use_default_notes = -1;
+		revs->show_notes_given = 1;
+		revs->notes_opt.use_default_notes = 1;
 	} else if (!strcmp(arg, "--no-standard-notes")) {
-		/* Deprecated */
 		revs->notes_opt.use_default_notes = 0;
 	} else if (!strcmp(arg, "--oneline")) {
 		revs->verbose_header = 1;
