'
+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