git-tag: Add --contains option

This functions similarly to "git branch --contains"; it will show all
tags that contain the specified commit, by sharing the same logic.

The patch also adds documentation and tests for the new option.

Signed-off-by: Jake Goulding <goulding@vivisimo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 115 insertions, 0 deletions

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index f377fea4b..69501e271 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -1090,6 +1090,121 @@ test_expect_success 'filename for the message is relative to cwd' '
 	git cat-file tag tag-from-subdir-2 | grep "in sub directory"
 '
 
+# create a few more commits to test --contains
+
+hash1=$(git rev-parse HEAD)
+
+test_expect_success 'creating second commit and tag' '
+	echo foo-2.0 >foo &&
+	git add foo &&
+	git commit -m second
+	git tag v2.0
+'
+
+hash2=$(git rev-parse HEAD)
+
+test_expect_success 'creating third commit without tag' '
+	echo foo-dev >foo &&
+	git add foo &&
+	git commit -m third
+'
+
+hash3=$(git rev-parse HEAD)
+
+# simple linear checks of --continue
+
+cat > expected <<EOF
+v0.2.1
+v1.0
+v1.0.1
+v1.1.3
+v2.0
+EOF
+
+test_expect_success 'checking that first commit is in all tags (hash)' "
+	git tag -l --contains $hash1 v* >actual
+	test_cmp expected actual
+"
+
+# other ways of specifying the commit
+test_expect_success 'checking that first commit is in all tags (tag)' "
+	git tag -l --contains v1.0 v* >actual
+	test_cmp expected actual
+"
+
+test_expect_success 'checking that first commit is in all tags (relative)' "
+	git tag -l --contains HEAD~2 v* >actual
+	test_cmp expected actual
+"
+
+cat > expected <<EOF
+v2.0
+EOF
+
+test_expect_success 'checking that second commit only has one tag' "
+	git tag -l --contains $hash2 v* >actual
+	test_cmp expected actual
+"
+
+
+cat > expected <<EOF
+EOF
+
+test_expect_success 'checking that third commit has no tags' "
+	git tag -l --contains $hash3 v* >actual
+	test_cmp expected actual
+"
+
+# how about a simple merge?
+
+test_expect_success 'creating simple branch' '
+	git branch stable v2.0 &&
+        git checkout stable &&
+	echo foo-3.0 > foo &&
+	git commit foo -m fourth
+	git tag v3.0
+'
+
+hash4=$(git rev-parse HEAD)
+
+cat > expected <<EOF
+v3.0
+EOF
+
+test_expect_success 'checking that branch head only has one tag' "
+	git tag -l --contains $hash4 v* >actual
+	test_cmp expected actual
+"
+
+test_expect_success 'merging original branch into this branch' '
+	git merge --strategy=ours master &&
+        git tag v4.0
+'
+
+cat > expected <<EOF
+v4.0
+EOF
+
+test_expect_success 'checking that original branch head has one tag now' "
+	git tag -l --contains $hash3 v* >actual
+	test_cmp expected actual
+"
+
+cat > expected <<EOF
+v0.2.1
+v1.0
+v1.0.1
+v1.1.3
+v2.0
+v3.0
+v4.0
+EOF
+
+test_expect_success 'checking that initial commit is in all tags' "
+	git tag -l --contains $hash1 v* >actual
+	test_cmp expected actual
+"
+
 # mixing modes and options:
 
 test_expect_success 'mixing incompatibles modes and options is forbidden' '