[PATCH v2 15/16] tag: implicitly supply --list given the -n option

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change the "tag" command to treat the "-n" invocation as a list-like
option in addition to --contains, --points-at etc.

Most of the work for this was done in my earlier "tag: Implicitly
supply --list given another list-like option" commit, but I've split
off this patch since it's more contentious. Now these will be
synonymous:

    git tag -n 100
    git tag -n --list 100

Whereas before the former would die. This doesn't technically
introduce any more ambiguity than the aforementioned change applied to
th other list-like options, but it does introduce the possibility for
more confusion, since instead of the latter of these dying:

    git tag -n100
    git tag -n 100

It now works entirely differently, i.e. invokes list mode with a
filter for "100" as a pattern. I.e. it's synonymous with:

    git tag -n --list 100

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 Documentation/git-tag.txt |  9 +++++----
 builtin/tag.c             |  3 ++-
 t/t7004-tag.sh            | 17 ++++++++++++++++-
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/Documentation/git-tag.txt b/Documentation/git-tag.txt
index c249072001..6694b7d33f 100644
--- a/Documentation/git-tag.txt
+++ b/Documentation/git-tag.txt
@@ -83,10 +83,11 @@ OPTIONS
 
 -n<num>::
 	<num> specifies how many lines from the annotation, if any,
-	are printed when using -l.
-	The default is not to print any annotation lines.
-	If no number is given to `-n`, only the first line is printed.
-	If the tag is not annotated, the commit message is displayed instead.
+	are printed when using -l. Implies `--list`.
++
+The default is not to print any annotation lines.
+If no number is given to `-n`, only the first line is printed.
+If the tag is not annotated, the commit message is displayed instead.
 
 -l::
 --list::
diff --git a/builtin/tag.c b/builtin/tag.c
index 67d63b2095..dbc6f5b74b 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -461,7 +461,8 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 		if (argc == 0)
 			cmdmode = 'l';
 		else if (filter.with_commit || filter.no_commit ||
-			 filter.points_at.nr || filter.merge_commit)
+			 filter.points_at.nr || filter.merge_commit ||
+			 filter.lines != -1)
 			cmdmode = 'l';
 	}
 
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 7984d1b495..60b5cd8751 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -639,6 +639,11 @@ test_expect_success \
 	git tag -n0 -l tag-one-line >actual &&
 	test_cmp expect actual &&
 
+	git tag -n0 | grep "^tag-one-line" >actual &&
+	test_cmp expect actual &&
+	git tag -n0 tag-one-line >actual &&
+	test_cmp expect actual &&
+
 	echo "tag-one-line    A msg" >expect &&
 	git tag -n1 -l | grep "^tag-one-line" >actual &&
 	test_cmp expect actual &&
@@ -652,6 +657,17 @@ test_expect_success \
 	test_cmp expect actual
 '
 
+test_expect_success 'The -n 100 invocation means -n --list 100, not -n100' '
+	>expect &&
+	git tag -n 100 >actual &&
+	test_cmp expect actual &&
+
+	git tag -m "A msg" 100 &&
+	echo "100             A msg" >expect &&
+	git tag -n 100 >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success \
 	'listing the zero-lines message of a non-signed tag should succeed' '
 	git tag -m "" tag-zero-lines &&
@@ -1569,7 +1585,6 @@ test_expect_success 'mixing incompatibles modes and options is forbidden' '
 	test_must_fail git tag -a -s -m -F &&
 	test_must_fail git tag -a -s -m -F -l &&
 	test_must_fail git tag -l -v &&
-	test_must_fail git tag -n 100 &&
 	test_must_fail git tag -n 100 -v &&
 	test_must_fail git tag -l -m msg &&
 	test_must_fail git tag -l -F some file &&
-- 
2.11.0