network/receivepack: Rename from receivepack

1 files changed, 1047 insertions, 0 deletions

diff --git a/network/receivepack/int_test.go b/network/receivepack/int_test.go
new file mode 100644
index 00000000..d17e6cd4
--- /dev/null
+++ b/network/receivepack/int_test.go
@@ -0,0 +1,1047 @@
+package receivepack_test
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"codeberg.org/lindenii/furgit/internal/testgit"
+	"codeberg.org/lindenii/furgit/network/protocol/pktline"
+	"codeberg.org/lindenii/furgit/network/protocol/sideband64k"
+	objectid "codeberg.org/lindenii/furgit/object/id"
+	receivepack "codeberg.org/lindenii/furgit/network/receivepack"
+	receivepackhooks "codeberg.org/lindenii/furgit/network/receivepack/hooks"
+)
+
+func TestReceivePackDeleteOnlyAtomicDeleteSucceeds(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00report-status atomic delete-refs object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			GitProtocol:     "",
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "ok refs/heads/main\n") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/main")
+		if err == nil {
+			t.Fatal("refs/heads/main still exists after delete push")
+		}
+	})
+}
+
+func TestReceivePackDeleteOnlyNonAtomicAppliesIndependentDeletes(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		_, _, staleID := testRepo.MakeCommit(t, "stale")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+		testRepo.UpdateRef(t, "refs/heads/topic", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			staleID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00report-status delete-refs object-format=" + algo.String() + "\n",
+		))
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/topic\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			GitProtocol:     "",
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "ng refs/heads/main ") || !strings.Contains(got, "ok refs/heads/topic\n") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/main")
+		if err != nil {
+			t.Fatalf("Resolve(main): %v", err)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/topic")
+		if err == nil {
+			t.Fatal("refs/heads/topic still exists after successful delete")
+		}
+	})
+}
+
+func TestReceivePackDeleteOnlyAtomicFailureLeavesAllRefsUntouched(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		_, _, staleID := testRepo.MakeCommit(t, "stale")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+		testRepo.UpdateRef(t, "refs/heads/topic", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			staleID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00report-status atomic delete-refs object-format=" + algo.String() + "\n",
+		))
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/topic\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			GitProtocol:     "",
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "ng refs/heads/main ") || !strings.Contains(got, "ng refs/heads/topic ") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/main")
+		if err != nil {
+			t.Fatalf("Resolve(main): %v", err)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/topic")
+		if err != nil {
+			t.Fatalf("Resolve(topic): %v", err)
+		}
+	})
+}
+
+func TestReceivePackAdvertisesResolvedHEAD(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+		testRepo.SymbolicRef(t, "HEAD", "refs/heads/main")
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+
+		want := commitID.String() + " HEAD"
+		if !strings.Contains(got, want) {
+			t.Fatalf("HEAD advertisement missing %q in %q", want, got)
+		}
+	})
+}
+
+func TestReceivePackVersion2FallsBackToV0(t *testing.T) {
+	t.Parallel()
+
+	testReceivePackProtocolFallback(t, "version=2")
+}
+
+func TestReceivePackHighestRequestedVersionFallsBackToV0ForV2(t *testing.T) {
+	t.Parallel()
+
+	testReceivePackProtocolFallback(t, "version=1:version=2")
+}
+
+func TestReceivePackWithoutReportStatusWritesNoStatusPayload(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00delete-refs atomic object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if strings.Contains(got, "unpack ") || strings.Contains(got, "ng refs/heads/main ") || strings.Contains(got, "ok refs/heads/main\n") {
+			t.Fatalf("unexpected status payload %q", got)
+		}
+	})
+}
+
+func testReceivePackProtocolFallback(t *testing.T, gitProtocol string) {
+	t.Helper()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00report-status atomic delete-refs object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			GitProtocol:     gitProtocol,
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		if strings.HasPrefix(output.String(), pktlineData("version 1\n")) {
+			t.Fatalf("receive-pack output started with protocol v1 preface for %q: %q", gitProtocol, output.String())
+		}
+	})
+}
+
+func TestReceivePackPackRequestWithoutObjectsRootReportsNotConfigured(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			commitID.String() + " " + commitID.String() + " refs/heads/main\x00report-status object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "unpack objects root not configured\n") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+	})
+}
+
+func TestReceivePackPackCreatePromotesObjectsAndUpdatesRef(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		sender := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := sender.MakeCommit(t, "pushed commit")
+
+		receiver := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo, Bare: true})
+		repo := receiver.OpenRepository(t)
+		objectsRoot := receiver.OpenObjectsRoot(t)
+
+		packStream := sender.PackObjectsReader(t, []string{commitID.String()}, false)
+		t.Cleanup(func() {
+			_ = packStream.Close()
+		})
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			objectid.Zero(algo).String() + " " + commitID.String() + " refs/heads/main\x00report-status-v2 atomic object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(
+			context.Background(),
+			&output,
+			io.MultiReader(strings.NewReader(input.String()), packStream),
+			receivepack.Options{
+				Algorithm:       algo,
+				Refs:            repo.Refs(),
+				ExistingObjects: repo.Objects(),
+				ObjectsRoot:     objectsRoot,
+			},
+		)
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "unpack ok\n") || !strings.Contains(got, "ok refs/heads/main\n") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+
+		reopened := receiver.OpenRepository(t)
+
+		resolved, err := reopened.Refs().ResolveToDetached("refs/heads/main")
+		if err != nil {
+			t.Fatalf("ResolveToDetached(main): %v", err)
+		}
+
+		if resolved.ID != commitID {
+			t.Fatalf("refs/heads/main = %s, want %s", resolved.ID, commitID)
+		}
+
+		if gotType := receiver.Run(t, "cat-file", "-t", commitID.String()); gotType != "commit" {
+			t.Fatalf("cat-file -t = %q, want commit", gotType)
+		}
+
+		packs := receiver.Run(t, "count-objects", "-v")
+		if !strings.Contains(packs, "packs: 1") {
+			t.Fatalf("count-objects output missing promoted pack: %q", packs)
+		}
+	})
+}
+
+func TestReceivePackHookSeesQuarantinedObjectsAndCanRejectBeforePromotion(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		sender := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := sender.MakeCommit(t, "pushed commit")
+
+		receiver := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo, Bare: true})
+		repo := receiver.OpenRepository(t)
+		objectsRoot := receiver.OpenObjectsRoot(t)
+
+		packStream := sender.PackObjectsReader(t, []string{commitID.String()}, false)
+		t.Cleanup(func() {
+			_ = packStream.Close()
+		})
+
+		var (
+			input      strings.Builder
+			output     bufferWriteFlusher
+			hookCalled bool
+		)
+
+		input.WriteString(pktlineData(
+			objectid.Zero(algo).String() + " " + commitID.String() + " refs/heads/main\x00report-status-v2 atomic object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(
+			context.Background(),
+			&output,
+			io.MultiReader(strings.NewReader(input.String()), packStream),
+			receivepack.Options{
+				Algorithm:       algo,
+				Refs:            repo.Refs(),
+				ExistingObjects: repo.Objects(),
+				ObjectsRoot:     objectsRoot,
+				Hook: func(ctx context.Context, req receivepack.HookRequest) ([]receivepack.UpdateDecision, error) {
+					hookCalled = true
+
+					if len(req.Updates) != 1 || req.Updates[0].NewID != commitID {
+						t.Fatalf("unexpected hook updates: %+v", req.Updates)
+					}
+
+					_, _, err := req.ExistingObjects.ReadHeader(commitID)
+					if err == nil {
+						t.Fatalf("existing objects unexpectedly contained quarantined commit %s", commitID)
+					}
+
+					_, _, err = req.QuarantinedObjects.ReadHeader(commitID)
+					if err != nil {
+						t.Fatalf("quarantined objects missing commit %s: %v", commitID, err)
+					}
+
+					return []receivepack.UpdateDecision{{
+						Accept:  false,
+						Message: "blocked by hook",
+					}}, nil
+				},
+			},
+		)
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		if !hookCalled {
+			t.Fatal("hook was not called")
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "unpack ok\n") || !strings.Contains(got, "ng refs/heads/main blocked by hook\n") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/main")
+		if err == nil {
+			t.Fatal("refs/heads/main exists after hook rejection")
+		}
+
+		packs := receiver.Run(t, "count-objects", "-v")
+		if !strings.Contains(packs, "packs: 0") {
+			t.Fatalf("count-objects output shows unexpected promoted pack: %q", packs)
+		}
+	})
+}
+
+func TestReceivePackHookCanRejectSubsetOfNonAtomicDeleteOnlyPush(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+		testRepo.UpdateRef(t, "refs/heads/topic", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00report-status delete-refs object-format=" + algo.String() + "\n",
+		))
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/topic\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+			Hook: func(ctx context.Context, req receivepack.HookRequest) ([]receivepack.UpdateDecision, error) {
+				return []receivepack.UpdateDecision{
+					{Accept: false, Message: "leave main alone"},
+					{Accept: true},
+				}, nil
+			},
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "ng refs/heads/main leave main alone\n") || !strings.Contains(got, "ok refs/heads/topic\n") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/main")
+		if err != nil {
+			t.Fatalf("Resolve(main): %v", err)
+		}
+
+		_, err = repo.Refs().Resolve("refs/heads/topic")
+		if err == nil {
+			t.Fatal("refs/heads/topic still exists after successful delete")
+		}
+	})
+}
+
+func TestReceivePackHookProgressUsesSideBand64K(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00report-status side-band-64k atomic delete-refs object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+			Hook: func(ctx context.Context, req receivepack.HookRequest) ([]receivepack.UpdateDecision, error) {
+				_, err := io.WriteString(req.IO.Progress, "hook says hello\n")
+				if err != nil {
+					return nil, err
+				}
+
+				return []receivepack.UpdateDecision{{Accept: true}}, nil
+			},
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		_, sidebandWire, ok := strings.Cut(output.String(), "0000")
+		if !ok {
+			t.Fatalf("output missing advertisement flush: %q", output.String())
+		}
+
+		dec := sideband64k.NewDecoder(strings.NewReader(sidebandWire), sideband64k.ReadOptions{})
+
+		sawHookProgress := false
+
+		var frame sideband64k.Frame
+
+		for {
+			var err error
+
+			frame, err = dec.ReadFrame()
+			if err != nil {
+				t.Fatalf("ReadFrame: %v", err)
+			}
+
+			if frame.Type == sideband64k.FrameProgress && string(frame.Payload) == "hook says hello\n" {
+				sawHookProgress = true
+			}
+
+			if frame.Type == sideband64k.FrameData {
+				break
+			}
+		}
+
+		if !sawHookProgress {
+			t.Fatal("missing hook progress frame")
+		}
+
+		statusDec := pktline.NewDecoder(strings.NewReader(string(frame.Payload)), pktline.ReadOptions{})
+
+		statusFrame, err := statusDec.ReadFrame()
+		if err != nil {
+			t.Fatalf("ReadFrame(status unpack): %v", err)
+		}
+
+		if statusFrame.Type != pktline.PacketData || string(statusFrame.Payload) != "unpack ok\n" {
+			t.Fatalf("status frame = %#v", statusFrame)
+		}
+	})
+}
+
+func TestReceivePackPredefinedRejectForcePushHookRejectsNonFastForward(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo, Bare: true})
+		_, treeID := testRepo.MakeSingleFileTree(t, "base.txt", []byte("base\n"))
+		baseID := testRepo.CommitTree(t, treeID, "base")
+		currentID := testRepo.CommitTree(t, treeID, "current", baseID)
+		forcedID := testRepo.CommitTree(t, treeID, "forced", baseID)
+		testRepo.UpdateRef(t, "refs/heads/main", currentID)
+
+		repo := testRepo.OpenRepository(t)
+		objectsRoot := testRepo.OpenObjectsRoot(t)
+		packStream := testRepo.PackObjectsReader(t, []string{forcedID.String(), "^" + currentID.String()}, false)
+		t.Cleanup(func() {
+			_ = packStream.Close()
+		})
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			currentID.String() + " " + forcedID.String() + " refs/heads/main\x00report-status atomic object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(
+			context.Background(),
+			&output,
+			io.MultiReader(strings.NewReader(input.String()), packStream),
+			receivepack.Options{
+				Algorithm:       algo,
+				Refs:            repo.Refs(),
+				ExistingObjects: repo.Objects(),
+				ObjectsRoot:     objectsRoot,
+				Hook:            receivepackhooks.RejectForcePush(),
+			},
+		)
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "ng refs/heads/main non-fast-forward\n") {
+			t.Fatalf("unexpected receive-pack output %q", got)
+		}
+
+		resolved, err := repo.Refs().ResolveToDetached("refs/heads/main")
+		if err != nil {
+			t.Fatalf("ResolveToDetached(main): %v", err)
+		}
+
+		if resolved.ID != currentID {
+			t.Fatalf("refs/heads/main = %s, want %s", resolved.ID, currentID)
+		}
+	})
+}
+
+func TestReceivePackReportStatusV2IncludesRefDetails(t *testing.T) {
+	t.Parallel()
+
+	//nolint:thelper
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		t.Parallel()
+
+		testRepo := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := testRepo.MakeCommit(t, "base")
+		testRepo.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := testRepo.OpenRepository(t)
+
+		var (
+			input  strings.Builder
+			output bufferWriteFlusher
+		)
+
+		input.WriteString(pktlineData(
+			commitID.String() + " " + objectid.Zero(algo).String() + " refs/heads/main\x00report-status-v2 atomic delete-refs object-format=" + algo.String() + "\n",
+		))
+		input.WriteString("0000")
+
+		err := receivepack.ReceivePack(context.Background(), &output, strings.NewReader(input.String()), receivepack.Options{
+			Algorithm:       algo,
+			Refs:            repo.Refs(),
+			ExistingObjects: repo.Objects(),
+		})
+		if err != nil {
+			t.Fatalf("ReceivePack: %v", err)
+		}
+
+		got := output.String()
+		if !strings.Contains(got, "option refname refs/heads/main\n") {
+			t.Fatalf("missing option refname in %q", got)
+		}
+
+		if !strings.Contains(got, "option old-oid "+commitID.String()+"\n") {
+			t.Fatalf("missing option old-oid in %q", got)
+		}
+
+		if !strings.Contains(got, "option new-oid "+objectid.Zero(algo).String()+"\n") {
+			t.Fatalf("missing option new-oid in %q", got)
+		}
+	})
+}
+
+func TestReceivePackGitPushCreatesBranch(t *testing.T) {
+	t.Parallel()
+
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) { //nolint:thelper
+		t.Parallel()
+
+		sender := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		_, _, commitID := sender.MakeCommit(t, "pushed commit")
+		sender.UpdateRef(t, "refs/heads/main", commitID)
+
+		receiver := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo, Bare: true})
+		repo := receiver.OpenRepository(t)
+		objectsRoot := receiver.OpenObjectsRoot(t)
+
+		stdout, stderr, clientErr, serverErr := runGitPushFD(
+			t,
+			sender,
+			receivepack.Options{
+				Algorithm:       algo,
+				Refs:            repo.Refs(),
+				ExistingObjects: repo.Objects(),
+				ObjectsRoot:     objectsRoot,
+			},
+			"push", "--porcelain", "fd::3,4/test", "refs/heads/main:refs/heads/main",
+		)
+		if clientErr != nil {
+			t.Fatalf("git push failed: %v\nstdout=%s\nstderr=%s", clientErr, stdout, stderr)
+		}
+
+		if serverErr != nil {
+			t.Fatalf("ReceivePack: %v", serverErr)
+		}
+
+		resolved, err := receiver.OpenRepository(t).Refs().ResolveToDetached("refs/heads/main")
+		if err != nil {
+			t.Fatalf("ResolveToDetached(main): %v", err)
+		}
+
+		if resolved.ID != commitID {
+			t.Fatalf("refs/heads/main = %s, want %s", resolved.ID, commitID)
+		}
+	})
+}
+
+func TestReceivePackGitPushRefUpdateWithoutNewObjectsSucceeds(t *testing.T) {
+	t.Parallel()
+
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) { //nolint:thelper
+		t.Parallel()
+
+		sender := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		blobID, treeID := sender.MakeSingleFileTree(t, "base.txt", []byte("base\n"))
+		commitID := sender.CommitTree(t, treeID, "base")
+		sender.UpdateRef(t, "refs/heads/main", commitID)
+
+		receiver := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo, Bare: true})
+		receiver.HashObject(t, "blob", sender.RunBytes(t, "cat-file", "blob", blobID.String()))
+		receiver.HashObject(t, "tree", sender.RunBytes(t, "cat-file", "tree", treeID.String()))
+		receiver.HashObject(t, "commit", sender.RunBytes(t, "cat-file", "commit", commitID.String()))
+		receiver.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := receiver.OpenRepository(t)
+		objectsRoot := receiver.OpenObjectsRoot(t)
+
+		stdout, stderr, clientErr, serverErr := runGitPushFD(
+			t,
+			sender,
+			receivepack.Options{
+				Algorithm:       algo,
+				Refs:            repo.Refs(),
+				ExistingObjects: repo.Objects(),
+				ObjectsRoot:     objectsRoot,
+			},
+			"push", "--porcelain", "fd::3,4/test", "refs/heads/main:refs/heads/topic",
+		)
+		if clientErr != nil {
+			t.Fatalf("git push failed: %v\nstdout=%s\nstderr=%s", clientErr, stdout, stderr)
+		}
+
+		if serverErr != nil {
+			t.Fatalf("ReceivePack: %v", serverErr)
+		}
+
+		resolved, err := receiver.OpenRepository(t).Refs().ResolveToDetached("refs/heads/topic")
+		if err != nil {
+			t.Fatalf("ResolveToDetached(topic): %v", err)
+		}
+
+		if resolved.ID != commitID {
+			t.Fatalf("refs/heads/topic = %s, want %s", resolved.ID, commitID)
+		}
+
+		packs := receiver.Run(t, "count-objects", "-v")
+		if !strings.Contains(packs, "packs: 0") {
+			t.Fatalf("count-objects output shows unexpected promoted pack: %q", packs)
+		}
+	})
+}
+
+func TestReceivePackGitPushAtomicDelete(t *testing.T) {
+	t.Parallel()
+
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) { //nolint:thelper
+		t.Parallel()
+
+		sender := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		receiver := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo, Bare: true})
+		_, _, commitID := receiver.MakeCommit(t, "base")
+		receiver.UpdateRef(t, "refs/heads/main", commitID)
+
+		repo := receiver.OpenRepository(t)
+
+		stdout, stderr, clientErr, serverErr := runGitPushFD(
+			t,
+			sender,
+			receivepack.Options{
+				Algorithm:       algo,
+				Refs:            repo.Refs(),
+				ExistingObjects: repo.Objects(),
+			},
+			"push", "--porcelain", "--atomic", "fd::3,4/test", ":refs/heads/main",
+		)
+		if clientErr != nil {
+			t.Fatalf("git push failed: %v\nstdout=%s\nstderr=%s", clientErr, stdout, stderr)
+		}
+
+		if serverErr != nil {
+			t.Fatalf("ReceivePack: %v", serverErr)
+		}
+
+		_, err := receiver.OpenRepository(t).Refs().Resolve("refs/heads/main")
+		if err == nil {
+			t.Fatal("refs/heads/main still exists after delete push")
+		}
+	})
+}
+
+func TestReceivePackGitPushRejectsForcedUpdateViaHook(t *testing.T) {
+	t.Parallel()
+
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) { //nolint:thelper
+		t.Parallel()
+
+		sender := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo})
+		blobID, treeID := sender.MakeSingleFileTree(t, "base.txt", []byte("base\n"))
+		baseID := sender.CommitTree(t, treeID, "base")
+		currentID := sender.CommitTree(t, treeID, "current", baseID)
+		forcedID := sender.CommitTree(t, treeID, "forced", baseID)
+		sender.UpdateRef(t, "refs/heads/main", forcedID)
+
+		receiver := testgit.NewRepo(t, testgit.RepoOptions{ObjectFormat: algo, Bare: true})
+		receiver.HashObject(t, "blob", sender.RunBytes(t, "cat-file", "blob", blobID.String()))
+		receiver.HashObject(t, "tree", sender.RunBytes(t, "cat-file", "tree", treeID.String()))
+		receiver.HashObject(t, "commit", sender.RunBytes(t, "cat-file", "commit", baseID.String()))
+		receiver.HashObject(t, "commit", sender.RunBytes(t, "cat-file", "commit", currentID.String()))
+		receiver.UpdateRef(t, "refs/heads/main", currentID)
+
+		repo := receiver.OpenRepository(t)
+		objectsRoot := receiver.OpenObjectsRoot(t)
+
+		stdout, stderr, clientErr, serverErr := runGitPushFD(
+			t,
+			sender,
+			receivepack.Options{
+				Algorithm:       algo,
+				Refs:            repo.Refs(),
+				ExistingObjects: repo.Objects(),
+				ObjectsRoot:     objectsRoot,
+				Hook:            receivepackhooks.RejectForcePush(),
+			},
+			"push", "--porcelain", "--force", "fd::3,4/test", "refs/heads/main:refs/heads/main",
+		)
+		if clientErr == nil {
+			t.Fatalf("git push unexpectedly succeeded\nstdout=%s\nstderr=%s", stdout, stderr)
+		}
+
+		if serverErr != nil {
+			t.Fatalf("ReceivePack: %v", serverErr)
+		}
+
+		if !strings.Contains(stdout, "non-fast-forward") && !strings.Contains(stderr, "non-fast-forward") {
+			t.Fatalf("git push output missing non-fast-forward message\nstdout=%s\nstderr=%s", stdout, stderr)
+		}
+
+		resolved, err := receiver.OpenRepository(t).Refs().ResolveToDetached("refs/heads/main")
+		if err != nil {
+			t.Fatalf("ResolveToDetached(main): %v", err)
+		}
+
+		if resolved.ID != currentID {
+			t.Fatalf("refs/heads/main = %s, want %s", resolved.ID, currentID)
+		}
+	})
+}
+
+type bufferWriteFlusher struct {
+	strings.Builder
+}
+
+func (bufferWriteFlusher) Flush() error {
+	return nil
+}
+
+func pktlineData(payload string) string {
+	return fmt.Sprintf("%04x%s", len(payload)+4, payload)
+}
+
+type fileWriteFlusher struct {
+	*os.File
+}
+
+func (fileWriteFlusher) Flush() error {
+	return nil
+}
+
+func runGitPushFD(
+	tb testing.TB,
+	sender *testgit.TestRepo,
+	opts receivepack.Options,
+	gitArgs ...string,
+) (stdout string, stderr string, clientErr error, serverErr error) {
+	tb.Helper()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	serverRead, clientWrite, err := os.Pipe()
+	if err != nil {
+		tb.Fatalf("os.Pipe(serverRead/clientWrite): %v", err)
+	}
+
+	clientRead, serverWrite, err := os.Pipe()
+	if err != nil {
+		tb.Fatalf("os.Pipe(clientRead/serverWrite): %v", err)
+	}
+
+	tb.Cleanup(func() {
+		_ = serverRead.Close()
+		_ = clientWrite.Close()
+		_ = clientRead.Close()
+		_ = serverWrite.Close()
+	})
+
+	go func() {
+		<-ctx.Done()
+
+		_ = serverRead.Close()
+		_ = clientWrite.Close()
+		_ = clientRead.Close()
+		_ = serverWrite.Close()
+	}()
+
+	serverErrCh := make(chan error, 1)
+
+	go func() {
+		defer func() {
+			_ = serverRead.Close()
+			_ = serverWrite.Close()
+		}()
+
+		serverErrCh <- receivepack.ReceivePack(
+			ctx,
+			fileWriteFlusher{serverWrite},
+			serverRead,
+			opts,
+		)
+	}()
+
+	stdoutBytes, stderrBytes, clientErr := sender.RunWithExtraFilesEnvContextE(
+		tb,
+		ctx,
+		nil,
+		[]*os.File{clientRead, clientWrite},
+		gitArgs...,
+	)
+	_ = clientRead.Close()
+	_ = clientWrite.Close()
+
+	serverErr = <-serverErrCh
+
+	if ctx.Err() != nil {
+		tb.Fatalf(
+			"git push fd:: timed out\nstdout=%s\nstderr=%s\nclientErr=%v\nserverErr=%v",
+			stdoutBytes,
+			stderrBytes,
+			clientErr,
+			serverErr,
+		)
+	}
+
+	return string(stdoutBytes), string(stderrBytes), clientErr, serverErr
+}