branch: let branch filters imply --list

Currently, a branch filter like `--contains`, `--merged`, or
`--no-merged` is ignored when we are not in listing mode.
For example:

  git branch --contains=foo bar

will create the branch "bar" from the current HEAD, ignoring
the `--contains` argument entirely. This is not very
helpful. There are two reasonable behaviors for git here:

  1. Flag an error; the arguments do not make sense.

  2. Implicitly go into `--list` mode

This patch chooses the latter, as it is more convenient, and
there should not be any ambiguity with attempting to create
a branch; using `--contains` and not wanting to list is
nonsensical.

That leaves the case where an explicit modification option
like `-d` is given.  We already catch the case where
`--list` is given alongside `-d` and flag an error. With
this patch, we will also catch the use of `--contains` and
other filter options alongside `-d`.

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

1 files changed, 35 insertions, 0 deletions

diff --git a/t/t3201-branch-contains.sh b/t/t3201-branch-contains.sh
index f86f4bc5e..141b0611e 100755
--- a/t/t3201-branch-contains.sh
+++ b/t/t3201-branch-contains.sh
@@ -55,6 +55,16 @@ test_expect_success 'branch --contains=side' '
 
 '
 
+test_expect_success 'branch --contains with pattern implies --list' '
+
+	git branch --contains=master master >actual &&
+	{
+		echo "  master"
+	} >expect &&
+	test_cmp expect actual
+
+'
+
 test_expect_success 'side: branch --merged' '
 
 	git branch --merged >actual &&
@@ -66,6 +76,16 @@ test_expect_success 'side: branch --merged' '
 
 '
 
+test_expect_success 'branch --merged with pattern implies --list' '
+
+	git branch --merged=side master >actual &&
+	{
+		echo "  master"
+	} >expect &&
+	test_cmp expect actual
+
+'
+
 test_expect_success 'side: branch --no-merged' '
 
 	git branch --no-merged >actual &&
@@ -95,4 +115,19 @@ test_expect_success 'master: branch --no-merged' '
 
 '
 
+test_expect_success 'branch --no-merged with pattern implies --list' '
+
+	git branch --no-merged=master master >actual &&
+	>expect &&
+	test_cmp expect actual
+
+'
+
+test_expect_success 'implicit --list conflicts with modification options' '
+
+	test_must_fail git branch --contains=master -d &&
+	test_must_fail git branch --contains=master -m foo
+
+'
+
 test_done