clone --single: limit the fetch refspec to fetched branch

After running "git clone --single", the resulting repository has the
usual default "+refs/heads/*:refs/remotes/origin/*" wildcard fetch
refspec installed, which means that a subsequent "git fetch" will
end up grabbing all the other branches.

Update the fetch refspec to cover only the singly cloned ref instead
to correct this.

That means:
If "--single" is used without "--branch" or "--mirror", the
fetch refspec covers the branch on which remote's HEAD points to.
If "--single" is used with "--branch", it'll cover only the branch
specified in the "--branch" option.
If "--single" is combined with "--mirror", then it'll cover all
refs of the cloned repository.
If "--single" is used with "--branch" that specifies a tag, then
it'll cover only the ref for this tag.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 156 insertions, 0 deletions

diff --git a/t/t5709-clone-refspec.sh b/t/t5709-clone-refspec.sh
new file mode 100755
index 0000000000..6f1ea984d4
--- /dev/null
+++ b/t/t5709-clone-refspec.sh
@@ -0,0 +1,156 @@
+#!/bin/sh
+
+test_description='test refspec written by clone-command'
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	# Make two branches, "master" and "side"
+	echo one >file &&
+	git add file &&
+	git commit -m one &&
+	echo two >file &&
+	git commit -a -m two &&
+	git tag two &&
+	echo three >file &&
+	git commit -a -m three &&
+	git checkout -b side &&
+	echo four >file &&
+	git commit -a -m four &&
+	git checkout master &&
+
+	# default clone
+	git clone . dir_all &&
+
+	# default --single that follows HEAD=master
+	git clone --single-branch . dir_master &&
+
+	# default --single that follows HEAD=side
+	git checkout side &&
+	git clone --single-branch . dir_side &&
+
+	# explicit --single that follows side
+	git checkout master &&
+	git clone --single-branch --branch side . dir_side2 &&
+
+	# default --single with --mirror
+	git clone --single-branch --mirror . dir_mirror &&
+
+	# default --single with --branch and --mirror
+	git clone --single-branch --mirror --branch side . dir_mirror_side &&
+
+	# --single that does not know what branch to follow
+	git checkout two^ &&
+	git clone --single-branch . dir_detached &&
+
+	# explicit --single with tag
+	git clone --single-branch --branch two . dir_tag &&
+
+	# advance both "master" and "side" branches
+	git checkout side &&
+	echo five >file &&
+	git commit -a -m five &&
+	git checkout master &&
+	echo six >file &&
+	git commit -a -m six &&
+
+	# update tag
+	git tag -d two && git tag two
+'
+
+test_expect_success 'by default all branches will be kept updated' '
+	(
+		cd dir_all && git fetch &&
+		git for-each-ref refs/remotes/origin |
+		sed -e "/HEAD$/d" \
+		    -e "s|/remotes/origin/|/heads/|" >../actual
+	) &&
+	# follow both master and side
+	git for-each-ref refs/heads >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'by default no tags will be kept updated' '
+	(
+		cd dir_all && git fetch &&
+		git for-each-ref refs/tags >../actual
+	) &&
+	git for-each-ref refs/tags >expect &&
+	test_must_fail test_cmp expect actual
+'
+
+test_expect_success '--single-branch while HEAD pointing at master' '
+	(
+		cd dir_master && git fetch &&
+		git for-each-ref refs/remotes/origin |
+		sed -e "/HEAD$/d" \
+		    -e "s|/remotes/origin/|/heads/|" >../actual
+	) &&
+	# only follow master
+	git for-each-ref refs/heads/master >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '--single-branch while HEAD pointing at side' '
+	(
+		cd dir_side && git fetch &&
+		git for-each-ref refs/remotes/origin |
+		sed -e "/HEAD$/d" \
+		    -e "s|/remotes/origin/|/heads/|" >../actual
+	) &&
+	# only follow side
+	git for-each-ref refs/heads/side >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '--single-branch with explicit --branch side' '
+	(
+		cd dir_side2 && git fetch &&
+		git for-each-ref refs/remotes/origin |
+		sed -e "/HEAD$/d" \
+		    -e "s|/remotes/origin/|/heads/|" >../actual
+	) &&
+	# only follow side
+	git for-each-ref refs/heads/side >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '--single-branch with explicit --branch with tag fetches updated tag' '
+	(
+		cd dir_tag && git fetch &&
+		git for-each-ref refs/tags >../actual
+	) &&
+	git for-each-ref refs/tags >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '--single-branch with --mirror' '
+	(
+		cd dir_mirror && git fetch &&
+		git for-each-ref refs > ../actual
+	) &&
+	git for-each-ref refs >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '--single-branch with explicit --branch and --mirror' '
+	(
+		cd dir_mirror_side && git fetch &&
+		git for-each-ref refs > ../actual
+	) &&
+	git for-each-ref refs >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '--single-branch with detached' '
+	(
+		cd dir_detached && git fetch &&
+		git for-each-ref refs/remotes/origin |
+		sed -e "/HEAD$/d" \
+		    -e "s|/remotes/origin/|/heads/|" >../actual
+	)
+	# nothing
+	>expect &&
+	test_cmp expect actual
+'
+
+test_done