Merge branch 'jc/push-to-checkout'

Extending the js/push-to-deploy topic, the behaviour of "git push"
when updating the working tree and the index with an update to the
branch that is checked out can be tweaked by push-to-checkout hook.

* jc/push-to-checkout:
  receive-pack: support push-to-checkout hook
  receive-pack: refactor updateInstead codepath

1 files changed, 63 insertions, 0 deletions

diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 85c7fecd2..e4436c170 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1434,4 +1434,67 @@ test_expect_success 'receive.denyCurrentBranch = updateInstead' '
 
 '
 
+test_expect_success 'updateInstead with push-to-checkout hook' '
+	rm -fr testrepo &&
+	git init testrepo &&
+	(
+		cd testrepo &&
+		git pull .. master &&
+		git reset --hard HEAD^^ &&
+		git tag initial &&
+		git config receive.denyCurrentBranch updateInstead &&
+		write_script .git/hooks/push-to-checkout <<-\EOF
+		echo >&2 updating from $(git rev-parse HEAD)
+		echo >&2 updating to "$1"
+
+		git update-index -q --refresh &&
+		git read-tree -u -m HEAD "$1" || {
+			status=$?
+			echo >&2 read-tree failed
+			exit $status
+		}
+		EOF
+	) &&
+
+	# Try pushing into a pristine
+	git push testrepo master &&
+	(
+		cd testrepo &&
+		git diff --quiet &&
+		git diff HEAD --quiet &&
+		test $(git -C .. rev-parse HEAD) = $(git rev-parse HEAD)
+	) &&
+
+	# Try pushing into a repository with conflicting change
+	(
+		cd testrepo &&
+		git reset --hard initial &&
+		echo conflicting >path2
+	) &&
+	test_must_fail git push testrepo master &&
+	(
+		cd testrepo &&
+		test $(git rev-parse initial) = $(git rev-parse HEAD) &&
+		test conflicting = "$(cat path2)" &&
+		git diff-index --quiet --cached HEAD
+	) &&
+
+	# Try pushing into a repository with unrelated change
+	(
+		cd testrepo &&
+		git reset --hard initial &&
+		echo unrelated >path1 &&
+		echo irrelevant >path5 &&
+		git add path5
+	) &&
+	git push testrepo master &&
+	(
+		cd testrepo &&
+		test "$(cat path1)" = unrelated &&
+		test "$(cat path5)" = irrelevant &&
+		test "$(git diff --name-only --cached HEAD)" = path5 &&
+		test $(git -C .. rev-parse HEAD) = $(git rev-parse HEAD)
+	)
+'
+
 test_done