fix(import): defensive handling for closed issues missing closed_at timestamp

Fixes GH#523: older versions of bd could close issues without setting
the closed_at timestamp. When importing such issues, validation would
fail with "closed issues must have closed_at timestamp".

This fix adds defensive handling in all issue creation/validation paths:
- If status is "closed" and closed_at is nil, set closed_at to
  max(created_at, updated_at) + 1 second
- Similarly for tombstones missing deleted_at

Applied to:
- batch_ops.go: validateBatchIssuesWithCustomStatuses (main import path)
- transaction.go: CreateIssue and CreateIssues
- queries.go: CreateIssue
- multirepo.go: upsertIssueInTx

Also adds comprehensive tests for the defensive fix.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/storage/sqlite/batch_ops.go

@@ -32,6 +32,27 @@ func validateBatchIssuesWithCustomStatuses(issues []*types.Issue, customStatuses
 			issue.UpdatedAt = now
 		}
 
+		// Defensive fix for closed_at invariant (GH#523): older versions of bd could
+		// close issues without setting closed_at. Fix by using max(created_at, updated_at) + 1s.
+		if issue.Status == types.StatusClosed && issue.ClosedAt == nil {
+			maxTime := issue.CreatedAt
+			if issue.UpdatedAt.After(maxTime) {
+				maxTime = issue.UpdatedAt
+			}
+			closedAt := maxTime.Add(time.Second)
+			issue.ClosedAt = &closedAt
+		}
+
+		// Defensive fix for deleted_at invariant: tombstones must have deleted_at
+		if issue.Status == types.StatusTombstone && issue.DeletedAt == nil {
+			maxTime := issue.CreatedAt
+			if issue.UpdatedAt.After(maxTime) {
+				maxTime = issue.UpdatedAt
+			}
+			deletedAt := maxTime.Add(time.Second)
+			issue.DeletedAt = &deletedAt
+		}
+
 		if err := issue.ValidateWithCustomStatuses(customStatuses); err != nil {
 			return fmt.Errorf("validation failed for issue %d: %w", i, err)
 		}

internal/storage/sqlite/batch_ops_test.go

@@ -480,3 +480,119 @@ func TestBulkOperations(t *testing.T) {
 		}
 	})
 }
+
+// TestDefensiveClosedAtFix tests GH#523 - closed issues without closed_at timestamp
+// from older versions of bd should be automatically fixed during import.
+func TestDefensiveClosedAtFix(t *testing.T) {
+	t.Run("sets closed_at for closed issues missing it", func(t *testing.T) {
+		now := time.Now()
+		pastTime := now.Add(-24 * time.Hour)
+
+		issues := []*types.Issue{
+			{
+				Title:     "Closed issue without closed_at",
+				Priority:  1,
+				IssueType: "task",
+				Status:    "closed",
+				CreatedAt: pastTime,
+				UpdatedAt: pastTime.Add(time.Hour),
+				// ClosedAt intentionally NOT set - simulating old bd data
+			},
+		}
+
+		err := validateBatchIssues(issues)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		// closed_at should be set to max(created_at, updated_at) + 1 second
+		if issues[0].ClosedAt == nil {
+			t.Fatal("closed_at should have been set")
+		}
+
+		expectedClosedAt := pastTime.Add(time.Hour).Add(time.Second)
+		if !issues[0].ClosedAt.Equal(expectedClosedAt) {
+			t.Errorf("closed_at mismatch: want %v, got %v", expectedClosedAt, *issues[0].ClosedAt)
+		}
+	})
+
+	t.Run("preserves existing closed_at", func(t *testing.T) {
+		now := time.Now()
+		pastTime := now.Add(-24 * time.Hour)
+		closedTime := pastTime.Add(2 * time.Hour)
+
+		issues := []*types.Issue{
+			{
+				Title:     "Closed issue with closed_at",
+				Priority:  1,
+				IssueType: "task",
+				Status:    "closed",
+				CreatedAt: pastTime,
+				UpdatedAt: pastTime.Add(time.Hour),
+				ClosedAt:  &closedTime,
+			},
+		}
+
+		err := validateBatchIssues(issues)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		// closed_at should be preserved
+		if !issues[0].ClosedAt.Equal(closedTime) {
+			t.Errorf("closed_at should be preserved: want %v, got %v", closedTime, *issues[0].ClosedAt)
+		}
+	})
+
+	t.Run("does not set closed_at for open issues", func(t *testing.T) {
+		issues := []*types.Issue{
+			{
+				Title:     "Open issue",
+				Priority:  1,
+				IssueType: "task",
+				Status:    "open",
+			},
+		}
+
+		err := validateBatchIssues(issues)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		if issues[0].ClosedAt != nil {
+			t.Error("closed_at should remain nil for open issues")
+		}
+	})
+
+	t.Run("sets deleted_at for tombstones missing it", func(t *testing.T) {
+		now := time.Now()
+		pastTime := now.Add(-24 * time.Hour)
+
+		issues := []*types.Issue{
+			{
+				Title:     "Tombstone without deleted_at",
+				Priority:  1,
+				IssueType: "task",
+				Status:    "tombstone",
+				CreatedAt: pastTime,
+				UpdatedAt: pastTime.Add(time.Hour),
+				// DeletedAt intentionally NOT set
+			},
+		}
+
+		err := validateBatchIssues(issues)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		// deleted_at should be set to max(created_at, updated_at) + 1 second
+		if issues[0].DeletedAt == nil {
+			t.Fatal("deleted_at should have been set")
+		}
+
+		expectedDeletedAt := pastTime.Add(time.Hour).Add(time.Second)
+		if !issues[0].DeletedAt.Equal(expectedDeletedAt) {
+			t.Errorf("deleted_at mismatch: want %v, got %v", expectedDeletedAt, *issues[0].DeletedAt)
+		}
+	})
+}

internal/storage/sqlite/multirepo.go

@@ -227,6 +227,27 @@ func (s *SQLiteStorage) importJSONLFile(ctx context.Context, jsonlPath, sourceRe
 // upsertIssueInTx inserts or updates an issue within a transaction.
 // Uses INSERT OR REPLACE to handle both new and existing issues.
 func (s *SQLiteStorage) upsertIssueInTx(ctx context.Context, tx *sql.Tx, issue *types.Issue, customStatuses []string) error {
+	// Defensive fix for closed_at invariant (GH#523): older versions of bd could
+	// close issues without setting closed_at. Fix by using max(created_at, updated_at) + 1s.
+	if issue.Status == types.StatusClosed && issue.ClosedAt == nil {
+		maxTime := issue.CreatedAt
+		if issue.UpdatedAt.After(maxTime) {
+			maxTime = issue.UpdatedAt
+		}
+		closedAt := maxTime.Add(time.Second)
+		issue.ClosedAt = &closedAt
+	}
+
+	// Defensive fix for deleted_at invariant: tombstones must have deleted_at
+	if issue.Status == types.StatusTombstone && issue.DeletedAt == nil {
+		maxTime := issue.CreatedAt
+		if issue.UpdatedAt.After(maxTime) {
+			maxTime = issue.UpdatedAt
+		}
+		deletedAt := maxTime.Add(time.Second)
+		issue.DeletedAt = &deletedAt
+	}
+
 	// Validate issue (with custom status support, bd-1pj6)
 	if err := issue.ValidateWithCustomStatuses(customStatuses); err != nil {
 		return fmt.Errorf("validation failed: %w", err)

internal/storage/sqlite/queries.go

@@ -50,16 +50,41 @@ func (s *SQLiteStorage) CreateIssue(ctx context.Context, issue *types.Issue, act
 		return fmt.Errorf("failed to get custom statuses: %w", err)
 	}
 
+	// Set timestamps first so defensive fixes can use them
+	now := time.Now()
+	if issue.CreatedAt.IsZero() {
+		issue.CreatedAt = now
+	}
+	if issue.UpdatedAt.IsZero() {
+		issue.UpdatedAt = now
+	}
+
+	// Defensive fix for closed_at invariant (GH#523): older versions of bd could
+	// close issues without setting closed_at. Fix by using max(created_at, updated_at) + 1s.
+	if issue.Status == types.StatusClosed && issue.ClosedAt == nil {
+		maxTime := issue.CreatedAt
+		if issue.UpdatedAt.After(maxTime) {
+			maxTime = issue.UpdatedAt
+		}
+		closedAt := maxTime.Add(time.Second)
+		issue.ClosedAt = &closedAt
+	}
+
+	// Defensive fix for deleted_at invariant: tombstones must have deleted_at
+	if issue.Status == types.StatusTombstone && issue.DeletedAt == nil {
+		maxTime := issue.CreatedAt
+		if issue.UpdatedAt.After(maxTime) {
+			maxTime = issue.UpdatedAt
+		}
+		deletedAt := maxTime.Add(time.Second)
+		issue.DeletedAt = &deletedAt
+	}
+
 	// Validate issue before creating (with custom status support)
 	if err := issue.ValidateWithCustomStatuses(customStatuses); err != nil {
 		return fmt.Errorf("validation failed: %w", err)
 	}
 
-	// Set timestamps
-	now := time.Now()
-	issue.CreatedAt = now
-	issue.UpdatedAt = now
-
 	// Compute content hash (bd-95)
 	if issue.ContentHash == "" {
 		issue.ContentHash = issue.ComputeContentHash()

internal/storage/sqlite/transaction.go

@@ -97,16 +97,41 @@ func (t *sqliteTxStorage) CreateIssue(ctx context.Context, issue *types.Issue, a
 		return fmt.Errorf("failed to get custom statuses: %w", err)
 	}
 
+	// Set timestamps first so defensive fixes can use them
+	now := time.Now()
+	if issue.CreatedAt.IsZero() {
+		issue.CreatedAt = now
+	}
+	if issue.UpdatedAt.IsZero() {
+		issue.UpdatedAt = now
+	}
+
+	// Defensive fix for closed_at invariant (GH#523): older versions of bd could
+	// close issues without setting closed_at. Fix by using max(created_at, updated_at) + 1s.
+	if issue.Status == types.StatusClosed && issue.ClosedAt == nil {
+		maxTime := issue.CreatedAt
+		if issue.UpdatedAt.After(maxTime) {
+			maxTime = issue.UpdatedAt
+		}
+		closedAt := maxTime.Add(time.Second)
+		issue.ClosedAt = &closedAt
+	}
+
+	// Defensive fix for deleted_at invariant: tombstones must have deleted_at
+	if issue.Status == types.StatusTombstone && issue.DeletedAt == nil {
+		maxTime := issue.CreatedAt
+		if issue.UpdatedAt.After(maxTime) {
+			maxTime = issue.UpdatedAt
+		}
+		deletedAt := maxTime.Add(time.Second)
+		issue.DeletedAt = &deletedAt
+	}
+
 	// Validate issue before creating (with custom status support)
 	if err := issue.ValidateWithCustomStatuses(customStatuses); err != nil {
 		return fmt.Errorf("validation failed: %w", err)
 	}
 
-	// Set timestamps
-	now := time.Now()
-	issue.CreatedAt = now
-	issue.UpdatedAt = now
-
 	// Compute content hash (bd-95)
 	if issue.ContentHash == "" {
 		issue.ContentHash = issue.ComputeContentHash()
@@ -185,11 +210,38 @@ func (t *sqliteTxStorage) CreateIssues(ctx context.Context, issues []*types.Issu
 	// Validate and prepare all issues first (with custom status support)
 	now := time.Now()
 	for _, issue := range issues {
+		// Set timestamps first so defensive fixes can use them
+		if issue.CreatedAt.IsZero() {
+			issue.CreatedAt = now
+		}
+		if issue.UpdatedAt.IsZero() {
+			issue.UpdatedAt = now
+		}
+
+		// Defensive fix for closed_at invariant (GH#523): older versions of bd could
+		// close issues without setting closed_at. Fix by using max(created_at, updated_at) + 1s.
+		if issue.Status == types.StatusClosed && issue.ClosedAt == nil {
+			maxTime := issue.CreatedAt
+			if issue.UpdatedAt.After(maxTime) {
+				maxTime = issue.UpdatedAt
+			}
+			closedAt := maxTime.Add(time.Second)
+			issue.ClosedAt = &closedAt
+		}
+
+		// Defensive fix for deleted_at invariant: tombstones must have deleted_at
+		if issue.Status == types.StatusTombstone && issue.DeletedAt == nil {
+			maxTime := issue.CreatedAt
+			if issue.UpdatedAt.After(maxTime) {
+				maxTime = issue.UpdatedAt
+			}
+			deletedAt := maxTime.Add(time.Second)
+			issue.DeletedAt = &deletedAt
+		}
+
 		if err := issue.ValidateWithCustomStatuses(customStatuses); err != nil {
 			return fmt.Errorf("validation failed for issue: %w", err)
 		}
-		issue.CreatedAt = now
-		issue.UpdatedAt = now
 		if issue.ContentHash == "" {
 			issue.ContentHash = issue.ComputeContentHash()
 		}