List the files under a path by path, not by string prefix (closes #223)

FileRepository.ListByPrefix matched with SQL LIKE: a plain string
prefix that ignores ASCII case and treats _ and % as wildcards.
Restoring /home/u/doc also restored doc2, DOC and doc.txt.bak, and a
backup counted the files of a longer sibling path as deleted. It is
now ListUnderPath, which returns the file at the path and every file
whose path starts with the path plus a slash, compared exactly. A
trailing slash is ignored, so "/" still lists every file.

Three tests relied on string-prefix matching and now name a full path
or call ListAll.

ListIDsWithChunksNotInUploadedBlobs keeps its LIKE: it only adds file
IDs the scan never looks up.

Model: opus-5-5

TODO.md

@@ -22,6 +22,17 @@ the tag exists and is exercised; what is left is merging `next` to
 
 # Completed Steps
 
+- 2026-10-06: Made a restore path argument select only that path and
+  what is beneath it
+  ([issue #223](https://git.eeqj.de/sneak/vaultik/issues/223)). The
+  lookup matched with SQL `LIKE`, so `/home/u/doc` also restored
+  `doc2`, `DOC` and `doc.txt.bak`, and a `_` or `%` in the path acted
+  as a wildcard. A backup used the same lookup to load the known files
+  of each configured path, so files of a longer sibling path were
+  counted as deleted. `FileRepository.ListUnderPath`, which replaces
+  `ListByPrefix`, returns the file at the path and every file whose
+  path starts with the path plus `/`, compared case-sensitively.
+
 - 2026-10-06: Made restore return an error instead of panicking on a
   malformed snapshot database
   ([issue #231](https://git.eeqj.de/sneak/vaultik/issues/231)). A chunk

internal/database/files.go

@@ -228,19 +228,24 @@ func (r *FileRepository) DeleteByID(
 	return nil
 }
 
-// ListByPrefix returns all files whose path starts with prefix, ordered by
-// path.
-func (r *FileRepository) ListByPrefix(
-	ctx context.Context, prefix string,
+// ListUnderPath returns the file at path and every file beneath it,
+// ordered by path. Paths are compared case-sensitively, and a trailing
+// slash on path is ignored, so "/" lists every file.
+func (r *FileRepository) ListUnderPath(
+	ctx context.Context, path string,
 ) ([]*File, error) {
+	path = strings.TrimRight(path, "/")
+	dirPrefix := path + "/"
+
+	// LIKE would ignore ASCII case and treat _ and % in path as wildcards.
 	query := `
 		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
-		WHERE path LIKE ? || '%'
+		WHERE path = ? OR substr(path, 1, length(?)) = ?
 		ORDER BY path
 	`
 
-	rows, err := r.db.conn.QueryContext(ctx, query, prefix)
+	rows, err := r.db.conn.QueryContext(ctx, query, path, dirPrefix, dirPrefix)
 	if err != nil {
 		return nil, fmt.Errorf("querying files: %w", err)
 	}

internal/database/files_test.go

@@ -5,10 +5,12 @@ import (
 	"database/sql"
 	"errors"
 	"os"
+	"slices"
 	"testing"
 	"time"
 
 	"sneak.berlin/go/vaultik/internal/database"
+	"sneak.berlin/go/vaultik/internal/types"
 )
 
 // errTestRollback is the sentinel returned from transaction bodies to
@@ -134,6 +136,82 @@ func TestFileRepositoryListDelete(t *testing.T) {
 	}
 }
 
+func TestFileRepositoryListUnderPath(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repo := database.NewFileRepository(db)
+
+	const (
+		docDir  = "/home/u/doc"
+		docFile = "/home/u/doc/a.txt"
+	)
+
+	// In path order, so the root case can expect all of them as listed.
+	paths := []string{
+		"/home/u/50%/x.txt",
+		"/home/u/50percent/y.txt",
+		"/home/u/DOC/c.txt",
+		"/home/u/a_b/x.txt",
+		"/home/u/axb/y.txt",
+		docDir,
+		"/home/u/doc.txt.bak",
+		docFile,
+		"/home/u/doc/sub/b.txt",
+		"/home/u/doc2/b.txt",
+	}
+
+	for _, path := range paths {
+		err := repo.Create(ctx, nil, &database.File{
+			Path:  types.FilePath(path),
+			MTime: time.Now().Truncate(time.Second),
+			Mode:  0644,
+		})
+		if err != nil {
+			t.Fatalf("failed to create %s: %v", path, err)
+		}
+	}
+
+	docTree := []string{docDir, docFile, "/home/u/doc/sub/b.txt"}
+
+	tests := []struct {
+		name string
+		path string
+		want []string
+	}{
+		{"directory", docDir, docTree},
+		{"directory with trailing slash", docDir + "/", docTree},
+		{"directory differing only in case", "/home/u/DOC",
+			[]string{"/home/u/DOC/c.txt"}},
+		{"file", docFile, []string{docFile}},
+		{"underscore is literal", "/home/u/a_b",
+			[]string{"/home/u/a_b/x.txt"}},
+		{"percent is literal", "/home/u/50%",
+			[]string{"/home/u/50%/x.txt"}},
+		{"root", "/", paths},
+	}
+
+	for _, tt := range tests {
+		files, err := repo.ListUnderPath(ctx, tt.path)
+		if err != nil {
+			t.Fatalf("%s: failed to list files: %v", tt.name, err)
+		}
+
+		got := make([]string, 0, len(files))
+		for _, f := range files {
+			got = append(got, f.Path.String())
+		}
+
+		if !slices.Equal(got, tt.want) {
+			t.Errorf("%s: listing %q got %q, want %q",
+				tt.name, tt.path, got, tt.want)
+		}
+	}
+}
+
 func TestFileRepositorySymlink(t *testing.T) {
 	t.Parallel()
 

internal/database/repository_comprehensive_test.go

@@ -824,7 +824,7 @@ func TestTransactionIsolation(t *testing.T) {
 	}
 
 	// Verify the file was not created (transaction rolled back)
-	files, err := repos.Files.ListByPrefix(ctx, "/tx-test")
+	files, err := repos.Files.ListUnderPath(ctx, "/tx-test.txt")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -916,7 +916,7 @@ func TestConcurrentOrphanedCleanup(t *testing.T) {
 	}
 
 	// Verify correct files were deleted
-	files, err := repos.Files.ListByPrefix(ctx, "/concurrent-")
+	files, err := repos.Files.ListAll(ctx)
 	if err != nil {
 		t.Fatal(err)
 	}

internal/database/repository_debug_test.go

@@ -147,7 +147,7 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	t.Logf("Files count after cleanup: %d", count)
 
 	// List remaining files
-	files, err := repos.Files.ListByPrefix(ctx, "/")
+	files, err := repos.Files.ListUnderPath(ctx, "/")
 	if err != nil {
 		t.Fatal(err)
 	}

internal/database/repository_edge_cases_test.go

@@ -442,12 +442,12 @@ func TestLargeDatasets(t *testing.T) {
 		createLargeDatasetFiles(t, repos, snapshot.ID.String(), fileCount)
 	})
 
-	// Test ListByPrefix performance
+	// Test ListUnderPath performance
 	//nolint:paralleltest // phases share one database and are order-dependent
-	t.Run("list by prefix performance", func(t *testing.T) {
+	t.Run("list under path performance", func(t *testing.T) {
 		start := time.Now()
 
-		files, err := repos.Files.ListByPrefix(ctx, "/large/")
+		files, err := repos.Files.ListUnderPath(ctx, "/large/")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -472,7 +472,7 @@ func TestLargeDatasets(t *testing.T) {
 		t.Logf("Cleaned up orphaned files in %v", time.Since(start))
 
 		// Verify correct number remain
-		files, err := repos.Files.ListByPrefix(ctx, "/large/")
+		files, err := repos.Files.ListUnderPath(ctx, "/large/")
 		if err != nil {
 			t.Fatal(err)
 		}

internal/snapshot/backup_test.go

@@ -71,7 +71,7 @@ func verifyBackupFiles(
 ) {
 	t.Helper()
 
-	files, err := repos.Files.ListByPrefix(ctx, "")
+	files, err := repos.Files.ListAll(ctx)
 	if err != nil {
 		t.Fatalf("Failed to list files: %v", err)
 	}

internal/snapshot/scanner.go

@@ -456,14 +456,16 @@ func (s *Scanner) finalizeScanResult(ctx context.Context, result *ScanResult) {
 	result.EndTime = time.Now().UTC()
 }
 
-// loadKnownFiles loads all known files from the database into a map for fast lookup
-// This avoids per-file database queries during the scan phase
+// loadKnownFiles loads the known files at and beneath path from the
+// database into a map for fast lookup. Every loaded file the scan does
+// not find is counted as deleted. This avoids per-file database queries
+// during the scan phase.
 func (s *Scanner) loadKnownFiles(
 	ctx context.Context, path string,
 ) (map[string]*database.File, error) {
-	files, err := s.repos.Files.ListByPrefix(ctx, path)
+	files, err := s.repos.Files.ListUnderPath(ctx, path)
 	if err != nil {
-		return nil, fmt.Errorf("listing files by prefix: %w", err)
+		return nil, fmt.Errorf("listing files under %s: %w", path, err)
 	}
 
 	result := make(map[string]*database.File, len(files))

internal/snapshot/scanner_test.go

@@ -71,7 +71,7 @@ func verifySimpleScanDatabase(
 	t.Helper()
 
 	// Verify files in database - includes regular files and directories
-	files, err := repos.Files.ListByPrefix(ctx, "/source")
+	files, err := repos.Files.ListUnderPath(ctx, "/source")
 	if err != nil {
 		t.Fatalf("failed to list files: %v", err)
 	}

internal/vaultik/integration_test.go

@@ -249,7 +249,7 @@ func verifyEndToEndBackupState(
 	assert.Positive(t, blobUploads, "Should upload at least one blob")
 
 	// Verify files in database
-	files, err := repos.Files.ListByPrefix(ctx, "/home/user")
+	files, err := repos.Files.ListUnderPath(ctx, "/home/user")
 	require.NoError(t, err)
 	// Count only regular files (not directories)
 	regularFiles := 0

internal/vaultik/restore.go

@@ -830,10 +830,9 @@ func (v *Vaultik) getFilesToRestore(
 		// Normalize the filter path
 		filter = filepath.Clean(filter)
 
-		// Get files with this prefix
-		files, err := repos.Files.ListByPrefix(ctx, filter)
+		files, err := repos.Files.ListUnderPath(ctx, filter)
 		if err != nil {
-			return nil, fmt.Errorf("listing files with prefix %s: %w", filter, err)
+			return nil, fmt.Errorf("listing files under %s: %w", filter, err)
 		}
 
 		for _, file := range files {