revision.c: support --notes command-line option

We already have --show-notes, but it has a few shortcomings:

  1. Using --show-notes=<ref> implies that we should also
     show the default notes. Which means you also need to
     use --no-standard-notes if you want to suppress them.

  2. It is negated by --no-notes, which doesn't match.

  3. It's too long to type. :)

This patch introduces --notes, which behaves exactly like
--show-notes, except that using "--notes=<ref>" does not
imply showing the default notes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

revision.c

@@ -1367,17 +1367,22 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->verbose_header = 1;
 		revs->pretty_given = 1;
 		get_commit_format(arg+9, revs);
-	} else if (!strcmp(arg, "--show-notes")) {
+	} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
 		revs->notes_opt.use_default_notes = 1;
-	} else if (!prefixcmp(arg, "--show-notes=")) {
+	} else if (!prefixcmp(arg, "--show-notes=") ||
+		   !prefixcmp(arg, "--notes=")) {
 		struct strbuf buf = STRBUF_INIT;
 		revs->show_notes = 1;
 		revs->show_notes_given = 1;
-		if (revs->notes_opt.use_default_notes < 0)
-			revs->notes_opt.use_default_notes = 1;
-		strbuf_addstr(&buf, arg+13);
+		if (!prefixcmp(arg, "--show-notes")) {
+			if (revs->notes_opt.use_default_notes < 0)
+				revs->notes_opt.use_default_notes = 1;
+			strbuf_addstr(&buf, arg+13);
+		}
+		else
+			strbuf_addstr(&buf, arg+8);
 		expand_notes_ref(&buf);
 		string_list_append(&revs->notes_opt.extra_notes_refs,
 				   strbuf_detach(&buf, NULL));

t/t3301-notes.sh

@@ -247,6 +247,28 @@ do
 	'
 done
 
+test_expect_success 'setup alternate notes ref' '
+	git notes --ref=alternate add -m alternate
+'
+
+test_expect_success 'git log --notes shows default notes' '
+	git log -1 --notes >output &&
+	grep xyzzy output &&
+	! grep alternate output
+'
+
+test_expect_success 'git log --notes=X shows only X' '
+	git log -1 --notes=alternate >output &&
+	! grep xyzzy output &&
+	grep alternate output
+'
+
+test_expect_success 'git log --notes --notes=X shows both' '
+	git log -1 --notes --notes=alternate >output &&
+	grep xyzzy output &&
+	grep alternate output
+'
+
 test_expect_success 'create -m notes (setup)' '
 	: > a5 &&
 	git add a5 &&