Artifact [943583090b]

Artifact 943583090b87734ea92e74f4ad95041d12f812871d1b311790e79048ea8c1138:

• File internal/manifest/manifest_test.go — part of check-in [0351167ae5] at 2026-07-23 10:41:36 on branch trunk — fix: zero-length file commit panic and stale missing-file carry-forward (#128)

  * fix: zero-length file commit panic and stale missing-file carry-forward

  Two related bugs in the checkin path:

  #68 - Committing a zero-length file panicked in blob.Store, which treated an empty artifact (a normal, well-known Fossil blob) as invalid input. Worse, manifest.Checkin's postcondition defer fired unconditionally during the panic's stack unwind and re-panicked with its own unrelated "manifestRid must be positive" message, masking the real cause. Fixed both: blob.Store now accepts zero-length (and nil) content, and Checkin's defer re-panics with the original panic value instead of asserting a postcondition that was never going to hold mid-unwind. Fixing the panic surfaced a second bug in the same family: buildCommitFiles used len(Content) > 0 to detect "already loaded from disk," which can't distinguish a genuinely empty file from one not yet loaded, so a newly added empty file failed with "no RID for unchanged file." Replaced the length sentinel with an explicit loaded-set.

  #79 - A tracked file deleted from disk without Unmanage/Remove was silently carried forward into the new manifest with its last-committed content, rather than being detected. Verified against fossil 2.28: canonical fails a commit when a missing tracked file is in scope (either the implicit "commit everything" case, or explicitly named), but leaves an out-of-scope missing file alone. buildCommitFiles now stats every in-scope tracked file before treating it as unchanged and errors clearly, naming the file, when it's gone; a file outside the commit's scope (relevant only to an explicit Enqueue) is left untouched exactly as before. Updated the two existing tests that had documented the old silent-carry-forward behavior as deliberately deferred to this issue.

  * fix: add CHANGELOG entry and unwrap-safe stat checks for #68/#79

  Adds the CHANGELOG entries the #79 acceptance criteria required for a user-visible behavior change (missing tracked file now hard-fails a commit instead of silently carrying stale content forward) and for the #68 zero-length-file panic fix.

  Also switches checkin.go's two os.IsNotExist(err) checks to errors.Is(err, os.ErrNotExist), which correctly unwraps the %w-wrapped os.ErrNotExist that MemStorage.Stat returns. Production was already correct (OSStorage.Stat returns a raw *PathError), but the tests were only exercising a generic fallback error branch instead of the intended "tracked file missing from disk" message. (user: [email protected], size: 40524) [annotate] [blame] [check-ins using]

package manifest

import (
	"bytes"
	"fmt"
	"path/filepath"
	"testing"
	"time"

	"github.com/danmestas/go-libfossil/db"
	"github.com/danmestas/go-libfossil/internal/blob"
	"github.com/danmestas/go-libfossil/internal/content"
	"github.com/danmestas/go-libfossil/internal/deck"
	"github.com/danmestas/go-libfossil/internal/delta"
	libfossil "github.com/danmestas/go-libfossil/internal/fsltype"
	"github.com/danmestas/go-libfossil/internal/repo"
	"github.com/danmestas/go-libfossil/internal/tag"
	_ "github.com/danmestas/go-libfossil/internal/testdriver"
	"github.com/danmestas/go-libfossil/simio"
	"github.com/danmestas/go-libfossil/testutil"
)

func setupTestRepo(t *testing.T) *repo.Repo {
	t.Helper()
	path := filepath.Join(t.TempDir(), "test.fossil")
	r, err := repo.Create(path, "testuser", simio.CryptoRand{}, "")
	if err != nil {
		t.Fatalf("repo.Create: %v", err)
	}
	t.Cleanup(func() { r.Close() })
	return r
}

func TestCheckinBasic(t *testing.T) {
	r := setupTestRepo(t)
	rid, uuid, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "hello.txt", Content: []byte("hello world")}},
		Comment: "initial commit",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 30, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin: %v", err)
	}
	if rid <= 0 {
		t.Fatalf("rid = %d", rid)
	}
	if len(uuid) != 40 && len(uuid) != 64 {
		t.Fatalf("uuid len = %d", len(uuid))
	}
	var comment string
	r.DB().QueryRow("SELECT comment FROM event WHERE objid=?", rid).Scan(&comment)
	if comment != "initial commit" {
		t.Fatalf("event comment = %q", comment)
	}
	var leafCount int
	r.DB().QueryRow("SELECT count(*) FROM leaf WHERE rid=?", rid).Scan(&leafCount)
	if leafCount != 1 {
		t.Fatalf("leaf count = %d", leafCount)
	}
}

// TestCheckinZeroLengthFile is a regression test for issue #68: committing
// a zero-length file used to panic in blob.Store, and Checkin's own
// postcondition defer masked that panic with an unrelated "manifestRid
// must be positive" message during unwind. A zero-length file is legal
// input and must commit like any other file.
func TestCheckinZeroLengthFile(t *testing.T) {
	r := setupTestRepo(t)
	rid, uuid, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "empty.txt", Content: []byte{}}},
		Comment: "empty file",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 30, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin(empty file): %v", err)
	}
	if rid <= 0 {
		t.Fatalf("rid = %d, want > 0", rid)
	}
	if len(uuid) != 40 && len(uuid) != 64 {
		t.Fatalf("uuid len = %d", len(uuid))
	}

	files, err := ListFiles(r, rid)
	if err != nil {
		t.Fatalf("ListFiles: %v", err)
	}
	if len(files) != 1 || files[0].Name != "empty.txt" {
		t.Fatalf("ListFiles = %+v, want one entry named empty.txt", files)
	}
	const emptySHA1 = "da39a3ee5e6b4b0d3255bfef95601890afd80709"
	if files[0].UUID != emptySHA1 {
		t.Fatalf("empty.txt UUID = %q, want %q", files[0].UUID, emptySHA1)
	}
}

func TestCheckinFossilRebuild(t *testing.T) {
	testutil.RequireFossilBin(t)
	r := setupTestRepo(t)
	_, _, err := Checkin(r, CheckinOpts{
		Files: []File{
			{Name: "hello.txt", Content: []byte("hello world")},
			{Name: "src/main.go", Content: []byte("package main\n")},
		},
		Comment: "initial commit",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 30, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin: %v", err)
	}
	r.Close()
	if err := testutil.FossilRebuild(r.Path()); err != nil {
		t.Fatalf("fossil rebuild: %v", err)
	}
}

func TestCheckinMultiple(t *testing.T) {
	r := setupTestRepo(t)
	rid1, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "file.txt", Content: []byte("v1")}},
		Comment: "first",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	rid2, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "file.txt", Content: []byte("v2")}},
		Comment: "second",
		User:    "testuser",
		Parent:  rid1,
		Time:    time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	var leafCount int
	r.DB().QueryRow("SELECT count(*) FROM leaf WHERE rid=?", rid1).Scan(&leafCount)
	if leafCount != 0 {
		t.Fatal("rid1 still a leaf")
	}
	r.DB().QueryRow("SELECT count(*) FROM leaf WHERE rid=?", rid2).Scan(&leafCount)
	if leafCount != 1 {
		t.Fatal("rid2 not a leaf")
	}
	var plinkCount int
	r.DB().QueryRow("SELECT count(*) FROM plink WHERE pid=? AND cid=?", rid1, rid2).Scan(&plinkCount)
	if plinkCount != 1 {
		t.Fatal("plink missing")
	}
}

func TestGetManifest(t *testing.T) {
	r := setupTestRepo(t)
	rid, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "hello.txt", Content: []byte("hello")}},
		Comment: "test commit",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 30, 0, 0, time.UTC),
	})
	d, err := GetManifest(r, rid)
	if err != nil {
		t.Fatalf("GetManifest: %v", err)
	}
	if d.C != "test commit" {
		t.Fatalf("C = %q", d.C)
	}
	if d.Type != deck.Checkin {
		t.Fatalf("Type = %d", d.Type)
	}
	if len(d.F) != 1 || d.F[0].Name != "hello.txt" {
		t.Fatalf("F = %+v", d.F)
	}
}

func TestListFilesBaseline(t *testing.T) {
	r := setupTestRepo(t)
	rid, _, _ := Checkin(r, CheckinOpts{
		Files: []File{
			{Name: "a.txt", Content: []byte("aaa")},
			{Name: "b.txt", Content: []byte("bbb")},
		},
		Comment: "initial",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	files, err := ListFiles(r, rid)
	if err != nil {
		t.Fatalf("ListFiles: %v", err)
	}
	if len(files) != 2 {
		t.Fatalf("count = %d", len(files))
	}
}

func TestLogMultiple(t *testing.T) {
	r := setupTestRepo(t)
	rid1, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v1")}},
		Comment: "first", User: "testuser",
		Time: time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	rid2, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v2")}},
		Comment: "second", User: "testuser", Parent: rid1,
		Time: time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	rid3, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v3")}},
		Comment: "third", User: "testuser", Parent: rid2,
		Time: time.Date(2024, 1, 15, 12, 0, 0, 0, time.UTC),
	})
	entries, err := Log(r, LogOpts{Start: rid3})
	if err != nil {
		t.Fatalf("Log: %v", err)
	}
	if len(entries) != 3 {
		t.Fatalf("count = %d", len(entries))
	}
	if entries[0].Comment != "third" || entries[2].Comment != "first" {
		t.Fatalf("order: %q %q %q", entries[0].Comment, entries[1].Comment, entries[2].Comment)
	}
}

func TestLogWithLimit(t *testing.T) {
	r := setupTestRepo(t)
	rid1, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v1")}},
		Comment: "first", User: "testuser",
		Time: time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	rid2, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v2")}},
		Comment: "second", User: "testuser", Parent: rid1,
		Time: time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	entries, _ := Log(r, LogOpts{Start: rid2, Limit: 1})
	if len(entries) != 1 {
		t.Fatalf("count = %d", len(entries))
	}
}

// TestLogNullUser covers fossil's optional U-card: a check-in manifest with
// no recorded user stores event.user as SQL NULL (the required cards for a
// check-in are only "DZ" — see manifest.c:130). Log must tolerate this and
// report an empty string, not fail the whole walk.
func TestLogNullUser(t *testing.T) {
	r := setupTestRepo(t)
	rid1, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v1")}},
		Comment: "first", User: "testuser",
		Time: time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	rid2, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v2")}},
		Comment: "second", User: "testuser", Parent: rid1,
		Time: time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if _, err := r.DB().Exec("UPDATE event SET user=NULL WHERE objid=?", rid2); err != nil {
		t.Fatalf("UPDATE event SET user=NULL: %v", err)
	}

	entries, err := Log(r, LogOpts{Start: rid2})
	if err != nil {
		t.Fatalf("Log: %v", err)
	}
	if len(entries) != 2 {
		t.Fatalf("count = %d, want 2", len(entries))
	}
	if entries[0].User != "" {
		t.Fatalf("entries[0].User = %q, want empty string for NULL event.user", entries[0].User)
	}
	if entries[0].Comment != "second" {
		t.Fatalf("entries[0].Comment = %q, want %q", entries[0].Comment, "second")
	}
	if entries[1].User != "testuser" {
		t.Fatalf("entries[1].User = %q, want %q (non-NULL users unchanged)", entries[1].User, "testuser")
	}
}

// TestLogNullComment covers fossil's optional C-card, the other realistic
// NULL candidate on the same event row (required cards remain only "DZ").
func TestLogNullComment(t *testing.T) {
	r := setupTestRepo(t)
	rid1, _, _ := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v1")}},
		Comment: "first", User: "testuser",
		Time: time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if _, err := r.DB().Exec("UPDATE event SET comment=NULL WHERE objid=?", rid1); err != nil {
		t.Fatalf("UPDATE event SET comment=NULL: %v", err)
	}

	entries, err := Log(r, LogOpts{Start: rid1})
	if err != nil {
		t.Fatalf("Log: %v", err)
	}
	if len(entries) != 1 {
		t.Fatalf("count = %d, want 1", len(entries))
	}
	if entries[0].Comment != "" {
		t.Fatalf("entries[0].Comment = %q, want empty string for NULL event.comment", entries[0].Comment)
	}
	if entries[0].User != "testuser" {
		t.Fatalf("entries[0].User = %q, want %q", entries[0].User, "testuser")
	}
}

func TestCheckinDelta(t *testing.T) {
	r := setupTestRepo(t)
	rid1, _, _ := Checkin(r, CheckinOpts{
		Files: []File{
			{Name: "a.txt", Content: []byte("aaa")},
			{Name: "b.txt", Content: []byte("bbb")},
		},
		Comment: "baseline", User: "testuser",
		Time: time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	rid2, _, err := Checkin(r, CheckinOpts{
		Files: []File{
			{Name: "a.txt", Content: []byte("aaa-modified")},
			{Name: "b.txt", Content: []byte("bbb")},
		},
		Comment: "delta", User: "testuser", Parent: rid1, Delta: true,
		Time: time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin delta: %v", err)
	}
	d, _ := GetManifest(r, rid2)
	if d.B == "" {
		t.Fatal("delta should have B-card")
	}
	if len(d.F) != 1 || d.F[0].Name != "a.txt" {
		t.Fatalf("delta F = %+v, want only a.txt", d.F)
	}
	files, _ := ListFiles(r, rid2)
	if len(files) != 2 {
		t.Fatalf("ListFiles = %d, want 2", len(files))
	}
}

func TestCheckinDeltaFossilRebuild(t *testing.T) {
	testutil.RequireFossilBin(t)
	r := setupTestRepo(t)
	rid1, _, _ := Checkin(r, CheckinOpts{
		Files: []File{
			{Name: "a.txt", Content: []byte("aaa")},
			{Name: "b.txt", Content: []byte("bbb")},
		},
		Comment: "baseline", User: "testuser",
		Time: time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	_, _, err := Checkin(r, CheckinOpts{
		Files: []File{
			{Name: "a.txt", Content: []byte("aaa-v2")},
			{Name: "b.txt", Content: []byte("bbb")},
			{Name: "c.txt", Content: []byte("new file")},
		},
		Comment: "delta with add", User: "testuser", Parent: rid1, Delta: true,
		Time: time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("delta: %v", err)
	}
	r.Close()
	if err := testutil.FossilRebuild(r.Path()); err != nil {
		t.Fatalf("rebuild: %v", err)
	}
}

func TestCheckinWithCustomTags(t *testing.T) {
	r := setupTestRepo(t)

	// Initial checkin (gets default trunk tags)
	rid1, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "file.txt", Content: []byte("v1")}},
		Comment: "initial",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("first checkin: %v", err)
	}

	// Second checkin with custom tags (branch creation)
	rid2, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "file.txt", Content: []byte("v2")}},
		Comment: "branch commit",
		User:    "testuser",
		Parent:  rid1,
		Time:    time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
		Tags: []deck.TagCard{
			{Type: deck.TagPropagating, Name: "branch", UUID: "*", Value: "feature-x"},
			{Type: deck.TagSingleton, Name: "sym-feature-x", UUID: "*"},
		},
	})
	if err != nil {
		t.Fatalf("second checkin: %v", err)
	}

	d, err := GetManifest(r, rid2)
	if err != nil {
		t.Fatalf("GetManifest: %v", err)
	}
	if len(d.T) != 2 {
		t.Fatalf("expected 2 tags, got %d: %+v", len(d.T), d.T)
	}

	// Verify the propagating branch tag
	found := false
	for _, tag := range d.T {
		if tag.Type == deck.TagPropagating && tag.Name == "branch" && tag.Value == "feature-x" {
			found = true
		}
	}
	if !found {
		t.Fatalf("missing propagating branch tag in %+v", d.T)
	}

	// Verify the singleton sym tag
	found = false
	for _, tag := range d.T {
		if tag.Type == deck.TagSingleton && tag.Name == "sym-feature-x" {
			found = true
		}
	}
	if !found {
		t.Fatalf("missing singleton sym-feature-x tag in %+v", d.T)
	}
}

func BenchmarkCheckin(b *testing.B) {
	path := filepath.Join(b.TempDir(), "bench.fossil")
	r, _ := repo.Create(path, "bench", simio.CryptoRand{}, "")
	defer r.Close()
	files := make([]File, 10)
	for i := range files {
		files[i] = File{Name: fmt.Sprintf("src/file%03d.go", i), Content: bytes.Repeat([]byte("x"), 1000)}
	}
	b.ResetTimer()
	var lastRid libfossil.FslID
	for i := 0; i < b.N; i++ {
		rid, _, _ := Checkin(r, CheckinOpts{
			Files: files, Comment: "bench", User: "bench",
			Parent: lastRid, Time: time.Now().UTC(),
		})
		lastRid = rid
	}
}

func BenchmarkListFiles(b *testing.B) {
	path := filepath.Join(b.TempDir(), "bench.fossil")
	r, _ := repo.Create(path, "bench", simio.CryptoRand{}, "")
	defer r.Close()
	files := make([]File, 50)
	for i := range files {
		files[i] = File{Name: fmt.Sprintf("src/file%03d.go", i), Content: []byte(fmt.Sprintf("c-%d", i))}
	}
	rid, _, _ := Checkin(r, CheckinOpts{
		Files: files, Comment: "bench", User: "bench", Time: time.Now().UTC(),
	})
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		ListFiles(r, rid)
	}
}

func TestCrosslinkInlineTCards(t *testing.T) {
	r := setupTestRepo(t)

	rid, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "hello.txt", Content: []byte("hello")}},
		Comment: "initial commit",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin: %v", err)
	}

	// Clear event and tagxref to simulate post-clone state (blobs exist, but not crosslinked).
	r.DB().Exec("DELETE FROM event")
	r.DB().Exec("DELETE FROM plink")
	r.DB().Exec("DELETE FROM leaf")
	r.DB().Exec("DELETE FROM mlink")
	r.DB().Exec("DELETE FROM tagxref")

	// Run Crosslink.
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	t.Logf("crosslinked %d artifacts", n)

	// Verify inline T-cards were processed.
	// Initial checkin adds: *branch trunk, +sym-trunk
	var branchCount int
	r.DB().QueryRow(
		"SELECT count(*) FROM tagxref JOIN tag USING(tagid) WHERE tagname='branch' AND rid=?", rid,
	).Scan(&branchCount)
	if branchCount != 1 {
		t.Errorf("branch tagxref count=%d, want 1", branchCount)
	}

	var symCount int
	r.DB().QueryRow(
		"SELECT count(*) FROM tagxref JOIN tag USING(tagid) WHERE tagname='sym-trunk' AND rid=?", rid,
	).Scan(&symCount)
	if symCount != 1 {
		t.Errorf("sym-trunk tagxref count=%d, want 1", symCount)
	}
}

func TestCrosslinkControlArtifact(t *testing.T) {
	r := setupTestRepo(t)

	rid, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "hello.txt", Content: []byte("hello")}},
		Comment: "initial commit",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin: %v", err)
	}

	// Create a control artifact via AddTag.
	_, err = tag.AddTag(r, tag.TagOpts{
		TargetRID: rid,
		TagName:   "testlabel",
		TagType:   tag.TagSingleton,
		Value:     "myvalue",
		User:      "testuser",
		Time:      time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("AddTag: %v", err)
	}

	// Clear tagxref to simulate post-clone.
	r.DB().Exec("DELETE FROM tagxref")

	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	t.Logf("crosslinked %d artifacts", n)

	// Verify control artifact's tag was re-applied.
	var count int
	r.DB().QueryRow(
		"SELECT count(*) FROM tagxref JOIN tag USING(tagid) WHERE tagname='testlabel' AND rid=?", rid,
	).Scan(&count)
	if count != 1 {
		t.Errorf("testlabel tagxref count=%d, want 1", count)
	}
}

func TestCrosslinkControlEventRow(t *testing.T) {
	r := setupTestRepo(t)

	// Create a checkin to target
	rid, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "hello.txt", Content: []byte("hello")}},
		Comment: "initial commit",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin: %v", err)
	}

	// Create a control artifact via AddTag
	controlRID, err := tag.AddTag(r, tag.TagOpts{
		TargetRID: rid,
		TagName:   "testlabel",
		TagType:   tag.TagSingleton,
		Value:     "myvalue",
		User:      "testuser",
		Time:      time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("AddTag: %v", err)
	}

	// Clear tagxref and event to simulate post-clone
	r.DB().Exec("DELETE FROM tagxref")
	r.DB().Exec("DELETE FROM event WHERE objid=?", controlRID)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify event row (type='g') exists for the control artifact
	var eventType, comment string
	err = r.DB().QueryRow(
		"SELECT type, comment FROM event WHERE objid=?", controlRID,
	).Scan(&eventType, &comment)
	if err != nil {
		t.Fatalf("event query: %v", err)
	}
	if eventType != "g" {
		t.Errorf("event type=%q, want 'g'", eventType)
	}
	if comment == "" {
		t.Errorf("event comment is empty, expected descriptive text")
	}
	t.Logf("event comment: %q", comment)
}

func TestDiscoveryQueryIdempotent(t *testing.T) {
	r := setupTestRepo(t)

	// Create a checkin.
	rid, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "hello.txt", Content: []byte("hello")}},
		Comment: "initial commit",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin: %v", err)
	}

	// Clear event and tagxref to simulate post-clone state.
	r.DB().Exec("DELETE FROM event")
	r.DB().Exec("DELETE FROM plink")
	r.DB().Exec("DELETE FROM leaf")
	r.DB().Exec("DELETE FROM mlink")
	r.DB().Exec("DELETE FROM tagxref")

	// First run should link artifacts.
	n1, err := Crosslink(r)
	if err != nil {
		t.Fatalf("first Crosslink: %v", err)
	}
	if n1 < 1 {
		t.Fatalf("first run linked %d, want >= 1", n1)
	}
	t.Logf("first run linked %d artifacts", n1)

	// Verify checkin was crosslinked.
	var eventCount int
	r.DB().QueryRow("SELECT count(*) FROM event WHERE objid=?", rid).Scan(&eventCount)
	if eventCount != 1 {
		t.Errorf("event count=%d, want 1", eventCount)
	}

	// Second run should link nothing (idempotent).
	n2, err := Crosslink(r)
	if err != nil {
		t.Fatalf("second Crosslink: %v", err)
	}
	if n2 != 0 {
		t.Errorf("second run linked %d, want 0 (idempotent)", n2)
	}
	t.Logf("second run linked %d artifacts (idempotent)", n2)
}

func TestCrosslinkCherrypick(t *testing.T) {
	r := setupTestRepo(t)

	// Create initial checkin
	rid1, uuid1, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "file.txt", Content: []byte("v1")}},
		Comment: "first",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("first Checkin: %v", err)
	}

	// Create second checkin (parent of cherrypick target)
	rid2, uuid2, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "file.txt", Content: []byte("v2")}},
		Comment: "second",
		User:    "testuser",
		Parent:  rid1,
		Time:    time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("second Checkin: %v", err)
	}

	// Manually create a manifest with Q-card (cherrypick)
	// Since Checkin doesn't support Q-cards, we construct the deck manually
	d := &deck.Deck{
		Type: deck.Checkin,
		C:    "cherrypick commit",
		D:    time.Date(2024, 1, 15, 12, 0, 0, 0, time.UTC),
		U:    deck.User("testuser"),
		P:    []string{uuid1}, // parent is rid1
		Q: []deck.CherryPick{
			{Target: uuid2, IsBackout: false}, // cherrypick rid2
		},
		F: []deck.FileCard{
			{Name: "file.txt", UUID: uuid2}, // use file from rid2
		},
	}

	// Compute R-card (manifest hash)
	d.R = "0000000000000000000000000000000000000000" // simplified for test

	// Marshal and store the manifest blob
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	rid3, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	// Clear crosslink tables to simulate post-clone
	r.DB().Exec("DELETE FROM event WHERE objid=?", rid3)
	r.DB().Exec("DELETE FROM plink WHERE cid=?", rid3)
	r.DB().Exec("DELETE FROM mlink WHERE mid=?", rid3)
	r.DB().Exec("DELETE FROM cherrypick WHERE childid=?", rid3)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify cherrypick table
	var count int
	r.DB().QueryRow(
		"SELECT count(*) FROM cherrypick WHERE parentid=? AND childid=? AND isExclude=0",
		rid2, rid3,
	).Scan(&count)
	if count != 1 {
		t.Errorf("cherrypick count=%d, want 1", count)
	}
}

func TestCrosslinkWiki(t *testing.T) {
	r := setupTestRepo(t)

	// Manually create a wiki manifest
	wikiTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	wikiContent := []byte("This is a test wiki page")
	d := &deck.Deck{
		Type: deck.Wiki,
		L:    "TestPage",
		U:    deck.User("testuser"),
		W:    wikiContent,
		D:    wikiTime,
	}

	// Marshal and store the wiki manifest blob
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	rid, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	// Clear crosslink tables to simulate post-clone
	r.DB().Exec("DELETE FROM event WHERE objid=?", rid)
	r.DB().Exec("DELETE FROM tagxref WHERE rid=?", rid)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify event row (type='w')
	var eventType, comment string
	err = r.DB().QueryRow(
		"SELECT type, comment FROM event WHERE objid=?", rid,
	).Scan(&eventType, &comment)
	if err != nil {
		t.Fatalf("event query: %v", err)
	}
	if eventType != "w" {
		t.Errorf("event type=%q, want 'w'", eventType)
	}
	if comment != "+TestPage" {
		t.Errorf("event comment=%q, want '+TestPage'", comment)
	}

	// Verify wiki-TestPage tag in tagxref
	var tagCount int
	r.DB().QueryRow(`
		SELECT count(*) FROM tagxref
		JOIN tag USING(tagid)
		WHERE tagname='wiki-TestPage' AND rid=?
	`, rid).Scan(&tagCount)
	if tagCount != 1 {
		t.Errorf("wiki-TestPage tag count=%d, want 1", tagCount)
	}
}

func TestCrosslinkTicket(t *testing.T) {
	r := setupTestRepo(t)

	// Manually create a ticket manifest
	ticketTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	ticketUUID := "0123456789abcdef0123456789abcdef01234567"
	d := &deck.Deck{
		Type: deck.Ticket,
		K:    ticketUUID,
		U:    deck.User("testuser"),
		D:    ticketTime,
		J: []deck.TicketField{
			{Name: "title", Value: "Test ticket"},
			{Name: "status", Value: "Open"},
		},
	}

	// Marshal and store the ticket manifest blob
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	rid, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	// Clear crosslink tables to simulate post-clone
	r.DB().Exec("DELETE FROM tagxref WHERE rid=?", rid)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify tkt-* tag in tagxref
	var tagCount int
	r.DB().QueryRow(`
		SELECT count(*) FROM tagxref
		JOIN tag USING(tagid)
		WHERE tagname=? AND rid=?
	`, fmt.Sprintf("tkt-%s", ticketUUID), rid).Scan(&tagCount)
	if tagCount != 1 {
		t.Errorf("tkt-%s tag count=%d, want 1", ticketUUID, tagCount)
	}
}

func TestCrosslinkEvent(t *testing.T) {
	r := setupTestRepo(t)

	// Manually create an event (technote) manifest
	eventTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	eventUUID := "fedcba9876543210fedcba9876543210fedcba98"
	eventBody := []byte("This is a technote body")
	d := &deck.Deck{
		Type: deck.Event,
		E: &deck.EventCard{
			Date: eventTime,
			UUID: eventUUID,
		},
		U: deck.User("testuser"),
		D: eventTime,
		W: eventBody,
		C: "Test technote",
	}

	// Marshal and store the event manifest blob
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	rid, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	// Clear crosslink tables to simulate post-clone
	r.DB().Exec("DELETE FROM event WHERE objid=?", rid)
	r.DB().Exec("DELETE FROM tagxref WHERE rid=?", rid)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify event row (type='e')
	var eventType, comment string
	err = r.DB().QueryRow(
		"SELECT type, comment FROM event WHERE objid=?", rid,
	).Scan(&eventType, &comment)
	if err != nil {
		t.Fatalf("event query: %v", err)
	}
	if eventType != "e" {
		t.Errorf("event type=%q, want 'e'", eventType)
	}
	if comment != "Test technote" {
		t.Errorf("event comment=%q, want 'Test technote'", comment)
	}

	// Verify event-* tag in tagxref
	var tagCount int
	r.DB().QueryRow(`
		SELECT count(*) FROM tagxref
		JOIN tag USING(tagid)
		WHERE tagname=? AND rid=?
	`, fmt.Sprintf("event-%s", eventUUID), rid).Scan(&tagCount)
	if tagCount != 1 {
		t.Errorf("event-%s tag count=%d, want 1", eventUUID, tagCount)
	}
}

func TestCrosslinkAttachment(t *testing.T) {
	r := setupTestRepo(t)

	// Manually create an attachment manifest with wiki target
	attachTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	d := &deck.Deck{
		Type: deck.Attachment,
		A: &deck.AttachmentCard{
			Filename: "test.txt",
			Target:   "TestPage",
			Source:   "abc123",
		},
		U: deck.User("testuser"),
		D: attachTime,
		C: "Attach test file",
	}

	// Marshal and store the attachment manifest blob
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	rid, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	// Clear crosslink tables to simulate post-clone
	r.DB().Exec("DELETE FROM attachment WHERE attachid=?", rid)
	r.DB().Exec("DELETE FROM event WHERE objid=?", rid)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify attachment table row
	var target, filename, src string
	var isLatestRaw any
	err = r.DB().QueryRow(
		"SELECT target, filename, src, isLatest FROM attachment WHERE attachid=?", rid,
	).Scan(&target, &filename, &src, &isLatestRaw)
	if err != nil {
		t.Fatalf("attachment query: %v", err)
	}
	if target != "TestPage" {
		t.Errorf("target=%q, want 'TestPage'", target)
	}
	if filename != "test.txt" {
		t.Errorf("filename=%q, want 'test.txt'", filename)
	}
	if src != "abc123" {
		t.Errorf("src=%q, want 'abc123'", src)
	}
	isLatest, _ := db.ScanInt(isLatestRaw)
	if isLatest != 1 {
		t.Errorf("isLatest=%d, want 1", isLatest)
	}

	// Verify event row (type='w' for wiki attachment)
	var eventType, comment string
	err = r.DB().QueryRow(
		"SELECT type, comment FROM event WHERE objid=?", rid,
	).Scan(&eventType, &comment)
	if err != nil {
		t.Fatalf("event query: %v", err)
	}
	if eventType != "w" {
		t.Errorf("event type=%q, want 'w'", eventType)
	}
	if comment != "Add attachment test.txt to wiki page TestPage" {
		t.Errorf("event comment=%q", comment)
	}
}

func TestCrosslinkCluster(t *testing.T) {
	r := setupTestRepo(t)

	// Store 2 blobs that will be members of the cluster
	blob1Data := []byte("test blob 1")
	rid1, uuid1, err := blob.Store(r.DB(), blob1Data)
	if err != nil {
		t.Fatalf("Store blob1: %v", err)
	}

	blob2Data := []byte("test blob 2")
	rid2, uuid2, err := blob.Store(r.DB(), blob2Data)
	if err != nil {
		t.Fatalf("Store blob2: %v", err)
	}

	// Verify both blobs are initially in unclustered table
	r.DB().Exec("INSERT OR IGNORE INTO unclustered(rid) VALUES(?)", rid1)
	r.DB().Exec("INSERT OR IGNORE INTO unclustered(rid) VALUES(?)", rid2)

	var count1, count2 int
	r.DB().QueryRow("SELECT count(*) FROM unclustered WHERE rid=?", rid1).Scan(&count1)
	r.DB().QueryRow("SELECT count(*) FROM unclustered WHERE rid=?", rid2).Scan(&count2)
	if count1 != 1 || count2 != 1 {
		t.Fatalf("blobs not in unclustered: rid1=%d rid2=%d", count1, count2)
	}

	// Create a cluster manifest with these two blobs as members
	clusterTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	d := &deck.Deck{
		Type: deck.Cluster,
		M:    []string{uuid1, uuid2},
		D:    clusterTime,
	}

	// Marshal and store the cluster manifest blob
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	rid, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	// Clear crosslink tables to simulate post-clone
	r.DB().Exec("DELETE FROM tagxref WHERE rid=?", rid)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify cluster tag
	var tagCount int
	r.DB().QueryRow(`
		SELECT count(*) FROM tagxref
		JOIN tag USING(tagid)
		WHERE tagname='cluster' AND rid=?
	`, rid).Scan(&tagCount)
	if tagCount != 1 {
		t.Errorf("cluster tag count=%d, want 1", tagCount)
	}

	// Verify both blobs were removed from unclustered table
	r.DB().QueryRow("SELECT count(*) FROM unclustered WHERE rid=?", rid1).Scan(&count1)
	r.DB().QueryRow("SELECT count(*) FROM unclustered WHERE rid=?", rid2).Scan(&count2)
	if count1 != 0 {
		t.Errorf("rid1 still in unclustered, count=%d", count1)
	}
	if count2 != 0 {
		t.Errorf("rid2 still in unclustered, count=%d", count2)
	}
}

func TestCrosslinkForum(t *testing.T) {
	r := setupTestRepo(t)

	// Create a forum post (thread starter)
	forumTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	forumContent := []byte("This is a test forum post")
	d := &deck.Deck{
		Type: deck.ForumPost,
		H:    "Discussion about sync",
		U:    deck.User("testuser"),
		W:    forumContent,
		D:    forumTime,
	}

	// Marshal and store the forum manifest blob
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	rid, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	// Clear crosslink tables to simulate post-clone
	r.DB().Exec("DELETE FROM event WHERE objid=?", rid)
	r.DB().Exec("DELETE FROM forumpost WHERE fpid=?", rid)

	// Run Crosslink
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	// Verify forumpost row with froot=self (thread starter)
	var froot int64
	var fprev, firt interface{}
	var fmtime float64
	err = r.DB().QueryRow(
		"SELECT froot, fprev, firt, fmtime FROM forumpost WHERE fpid=?", rid,
	).Scan(&froot, &fprev, &firt, &fmtime)
	if err != nil {
		t.Fatalf("forumpost query: %v", err)
	}
	if froot != int64(rid) {
		t.Errorf("froot=%d, want %d (self)", froot, rid)
	}
	if fprev != nil {
		t.Errorf("fprev=%v, want nil (no previous edit)", fprev)
	}
	if firt != nil {
		t.Errorf("firt=%v, want nil (thread starter)", firt)
	}

	// Verify event row (type='f')
	var eventType, comment string
	err = r.DB().QueryRow(
		"SELECT type, comment FROM event WHERE objid=?", rid,
	).Scan(&eventType, &comment)
	if err != nil {
		t.Fatalf("event query: %v", err)
	}
	if eventType != "f" {
		t.Errorf("event type=%q, want 'f'", eventType)
	}
	if comment != "Post: Discussion about sync" {
		t.Errorf("event comment=%q, want 'Post: Discussion about sync'", comment)
	}
}

// TestCrosslinkForumPostTableDropped reproduces #103: canonical `fossil
// rebuild` drops on-demand tables it did not populate, including forumpost,
// so a repository handed to us straight out of a rebuild may not have the
// table at all. Crosslink must create it on demand the way canonical does,
// rather than erroring with "no such table: forumpost".
func TestCrosslinkForumPostTableDropped(t *testing.T) {
	r := setupTestRepo(t)

	// Simulate a repository straight out of a canonical rebuild that never
	// saw a forum post: the table does not exist at all.
	if _, err := r.DB().Exec("DROP TABLE forumpost"); err != nil {
		t.Fatalf("drop forumpost: %v", err)
	}

	forumTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	d := &deck.Deck{
		Type: deck.ForumPost,
		H:    "Discussion about sync",
		U:    deck.User("testuser"),
		W:    []byte("This is a test forum post"),
		D:    forumTime,
	}
	manifestBytes, err := d.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}
	rid, _, err := blob.Store(r.DB(), manifestBytes)
	if err != nil {
		t.Fatalf("Store manifest: %v", err)
	}

	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 1 {
		t.Fatalf("expected at least 1 artifact crosslinked, got %d", n)
	}

	var froot int64
	if err := r.DB().QueryRow("SELECT froot FROM forumpost WHERE fpid=?", rid).Scan(&froot); err != nil {
		t.Fatalf("forumpost query: %v", err)
	}
	if froot != int64(rid) {
		t.Errorf("froot=%d, want %d (self)", froot, rid)
	}
}

func TestCrosslinkTwoPass(t *testing.T) {
	r := setupTestRepo(t)

	// Store a wiki manifest blob (Type=Wiki, L="TwoPassPage", U="test", W=content, D=time).
	wikiTime := time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC)
	wikiContent := []byte("Two-pass wiki content")
	wikiDeck := &deck.Deck{
		Type: deck.Wiki,
		L:    "TwoPassPage",
		U:    deck.User("testuser"),
		W:    wikiContent,
		D:    wikiTime,
	}
	wikiBytes, err := wikiDeck.Marshal()
	if err != nil {
		t.Fatalf("Marshal wiki: %v", err)
	}
	wikiRid, _, err := blob.Store(r.DB(), wikiBytes)
	if err != nil {
		t.Fatalf("Store wiki: %v", err)
	}

	// Create a checkin via Checkin().
	checkinRid, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "file.txt", Content: []byte("checkin content")}},
		Comment: "test checkin",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin: %v", err)
	}

	// Clear all event and tagxref rows to simulate post-clone state.
	r.DB().Exec("DELETE FROM event")
	r.DB().Exec("DELETE FROM tagxref")
	r.DB().Exec("DELETE FROM plink")
	r.DB().Exec("DELETE FROM leaf")
	r.DB().Exec("DELETE FROM mlink")

	// Call Crosslink once.
	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n < 2 {
		t.Fatalf("expected n >= 2 artifacts crosslinked, got %d", n)
	}
	t.Logf("crosslinked %d artifacts", n)

	// Verify: wiki event type='w' exists.
	var wikiEventType string
	err = r.DB().QueryRow("SELECT type FROM event WHERE objid=?", wikiRid).Scan(&wikiEventType)
	if err != nil {
		t.Errorf("wiki event query: %v", err)
	} else if wikiEventType != "w" {
		t.Errorf("wiki event type=%q, want 'w'", wikiEventType)
	}

	// Verify: checkin event type='ci' exists.
	var checkinEventType string
	err = r.DB().QueryRow("SELECT type FROM event WHERE objid=?", checkinRid).Scan(&checkinEventType)
	if err != nil {
		t.Errorf("checkin event query: %v", err)
	} else if checkinEventType != "ci" {
		t.Errorf("checkin event type=%q, want 'ci'", checkinEventType)
	}
}

// forceDeltify rewrites rid as a delta against srcRid, the same way
// content.Deltify would, without content.Deltify's size/ratio gate --
// exercising that gate isn't the point of the tests that use this, only
// forcing candidates into a genuine delta relationship so Crosslink's
// delta-chain-order sweep has something to reorder around. Mirrors
// deltifyWrite (internal/content/deltify.go) exactly: compress the delta
// bytes over the blob row, link it in delta, and verify the round trip
// through content.Expand before trusting it.
func forceDeltify(t *testing.T, r *repo.Repo, rid, srcRid libfossil.FslID) {
	t.Helper()
	data, err := content.Expand(r.DB(), rid)
	if err != nil {
		t.Fatalf("forceDeltify: expand rid=%d: %v", rid, err)
	}
	src, err := content.Expand(r.DB(), srcRid)
	if err != nil {
		t.Fatalf("forceDeltify: expand srcid=%d: %v", srcRid, err)
	}
	deltaBytes := delta.Create(src, data)
	compressed, err := blob.Compress(deltaBytes)
	if err != nil {
		t.Fatalf("forceDeltify: compress: %v", err)
	}
	if err := r.WithTx(func(tx *db.Tx) error {
		if _, err := tx.Exec("UPDATE blob SET content=? WHERE rid=?", compressed, rid); err != nil {
			return err
		}
		_, err := tx.Exec("REPLACE INTO delta(rid, srcid) VALUES(?, ?)", rid, srcRid)
		return err
	}); err != nil {
		t.Fatalf("forceDeltify: %v", err)
	}
	if _, err := content.Expand(r.DB(), rid); err != nil {
		t.Fatalf("forceDeltify: round-trip verify rid=%d: %v", rid, err)
	}
}

// TestCrosslinkReversedDeltaOrderStillPropagatesAndLeafs is the #102
// regression: manifest.Checkin deltifies each checkin's parent manifest
// against the new one it just wrote (content.Deltify(parent, this)), so in
// a repository old enough for that to take, the chain root is the newest
// commit and the deepest ancestor is the oldest -- forced here directly
// with forceDeltify rather than relying on real commits being large and
// similar enough for content.Deltify's own size/ratio gate to take the
// delta, which is a orthogonal concern this test doesn't need to exercise.
// Once the derived tables are cleared to simulate a fresh clone, Crosslink's
// delta-chain-order sweep visits v3 first and v1 last -- the exact reverse
// of commit order, and the opposite of what the old per-checkin
// PropagateAll(parent) and incremental leaf bookkeeping assumed. tagxref and
// leaf must still come out correct: v1's propagating branch tag on all
// three, and only v3 marked a leaf.
func TestCrosslinkReversedDeltaOrderStillPropagatesAndLeafs(t *testing.T) {
	r := setupTestRepo(t)

	v1, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v1 content")}},
		Comment: "v1",
		User:    "testuser",
		Time:    time.Date(2024, 1, 15, 10, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin v1: %v", err)
	}
	v2, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v2 content")}},
		Comment: "v2",
		User:    "testuser",
		Parent:  v1,
		Time:    time.Date(2024, 1, 15, 11, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin v2: %v", err)
	}
	v3, _, err := Checkin(r, CheckinOpts{
		Files:   []File{{Name: "a.txt", Content: []byte("v3 content")}},
		Comment: "v3",
		User:    "testuser",
		Parent:  v2,
		Time:    time.Date(2024, 1, 15, 12, 0, 0, 0, time.UTC),
	})
	if err != nil {
		t.Fatalf("Checkin v3: %v", err)
	}

	forceDeltify(t, r, v1, v2)
	forceDeltify(t, r, v2, v3)

	// Reset to the state a fresh clone is in right before crosslinking.
	for _, tbl := range crosslinkDerivedTables {
		if _, err := r.DB().Exec("DELETE FROM " + tbl); err != nil {
			t.Fatalf("clear %s: %v", tbl, err)
		}
	}

	n, err := Crosslink(r)
	if err != nil {
		t.Fatalf("Crosslink: %v", err)
	}
	if n != 3 {
		t.Fatalf("linked=%d, want 3", n)
	}

	for _, rid := range []libfossil.FslID{v1, v2, v3} {
		var value string
		err := r.DB().QueryRow(`
			SELECT value FROM tagxref
			JOIN tag USING(tagid)
			WHERE tagname='branch' AND rid=?
		`, rid).Scan(&value)
		if err != nil {
			t.Errorf("rid=%d: branch tag missing: %v", rid, err)
		} else if value != "trunk" {
			t.Errorf("rid=%d: branch tag=%q, want %q", rid, value, "trunk")
		}
	}

	var leafRids []libfossil.FslID
	rows, err := r.DB().Query("SELECT rid FROM leaf ORDER BY rid")
	if err != nil {
		t.Fatalf("leaf query: %v", err)
	}
	for rows.Next() {
		var rid libfossil.FslID
		if err := rows.Scan(&rid); err != nil {
			t.Fatalf("leaf scan: %v", err)
		}
		leafRids = append(leafRids, rid)
	}
	rows.Close()
	if len(leafRids) != 1 || leafRids[0] != v3 {
		t.Errorf("leaf=%v, want [%d] (v3 only)", leafRids, v3)
	}
}