tag: change misleading --list <pattern> documentation

Change the documentation for --list so that it's described as a
toggle, not as an option that takes a <pattern> as an argument.

Junio initially documented this in b867c7c23a ("git-tag: -l to list
tags (usability).", 2006-02-17), but later Jeff King changed "tag" to
accept multiple patterns in 588d0e834b ("tag: accept multiple patterns
for --list", 2011-06-20).

However, documenting this as "-l <pattern>" was never correct, as
these both worked before Jeff's change:

    git tag -l 'v*'
    git tag 'v*' -l

One would expect an option that was documented like that to only
accept:

    git tag --list
    git tag --list 'v*rc*'

And after Jeff's change, one that took multiple patterns:

    git tag --list 'v*rc*' --list '*2.8*'

But since it's actually a toggle all of these work as well, and
produce identical output to the last example above:

    git tag --list 'v*rc*' '*2.8*'
    git tag --list 'v*rc*' '*2.8*' --list --list --list
    git tag --list 'v*rc*' '*2.8*' --list -l --list -l --list

Now the documentation is more in tune with how the "branch" command
describes its --list option since commit cddd127b9a ("branch:
introduce --list option", 2011-08-28).

Change the test suite to assert that these invocations work for the
cases that weren't already being tested for.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-tag.txt

@@ -87,13 +87,14 @@ OPTIONS
 	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 <pattern>::
---list <pattern>::
-	List tags with names that match the given pattern (or all if no
-	pattern is given).  Running "git tag" without arguments also
-	lists all tags. The pattern is a shell wildcard (i.e., matched
-	using fnmatch(3)).  Multiple patterns may be given; if any of
-	them matches, the tag is shown.
+-l::
+--list::
+	List tags. With optional `<pattern>...`, e.g. `git tag --list
+	'v-*'`, list only the tags that match the pattern(s).
++
+Running "git tag" without arguments also lists all tags. The pattern
+is a shell wildcard (i.e., matched using fnmatch(3)). Multiple
+patterns may be given; if any of them matches, the tag is shown.
 
 --sort=<key>::
 	Sort based on the key given.  Prefix `-` to sort in

t/t7004-tag.sh

@@ -118,6 +118,18 @@ test_expect_success 'listing all tags if one exists should succeed' '
 	git tag
 '
 
+cat >expect <<EOF
+mytag
+EOF
+test_expect_success 'Multiple -l or --list options are equivalent to one -l option' '
+	git tag -l -l >actual &&
+	test_cmp expect actual &&
+	git tag --list --list >actual &&
+	test_cmp expect actual &&
+	git tag --list -l --list >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'listing all tags if one exists should output that tag' '
 	test $(git tag -l) = mytag &&
 	test $(git tag) = mytag
@@ -336,6 +348,19 @@ test_expect_success 'tag -l can accept multiple patterns' '
 	test_cmp expect actual
 '
 
+# Between v1.7.7 & v2.13.0 a fair reading of the git-tag documentation
+# could leave you with the impression that "-l <pattern> -l <pattern>"
+# was how we wanted to accept multiple patterns.
+#
+# This test should not imply that this is a sane thing to support. but
+# since the documentation was worded like it was let's at least find
+# out if we're going to break this long-documented form of taking
+# multiple patterns.
+test_expect_success 'tag -l <pattern> -l <pattern> works, as our buggy documentation previously suggested' '
+	git tag -l "v1*" -l "v0*" >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'listing tags in column' '
 	COLUMNS=40 git tag -l --column=row >actual &&
 	cat >expected <<\EOF &&