Fix inconsistent object genration in object.FromEvent()

The object shouldn't be added to the cache store before committing the
ongoing database transaction. Apart from that, this commit ensures that
the object in memory state represents the information stored in the DB.

internal/object/object.go

@@ -120,11 +120,17 @@ func FromEvent(ctx context.Context, db *database.DB, ev *event.Event) (*Object,
 	cacheMu.Lock()
 	defer cacheMu.Unlock()
 
-	object, ok := cache[id.String()]
-	if !ok {
-		object = New(db, ev)
-		object.ID = id
-		cache[id.String()] = object
+	newObject := new(Object)
+	object, objectExists := cache[id.String()]
+	if !objectExists {
+		newObject = New(db, ev)
+		newObject.ID = id
+	} else {
+		*newObject = *object
+
+		newObject.ExtraTags = ev.ExtraTags
+		newObject.Name = ev.Name
+		newObject.URL = utils.ToDBString(ev.URL)
 	}
 
 	tx, err := db.BeginTxx(ctx, nil)
@@ -133,27 +139,27 @@ func FromEvent(ctx context.Context, db *database.DB, ev *event.Event) (*Object,
 	}
 	defer func() { _ = tx.Rollback() }()
 
-	stmt, _ := object.db.BuildUpsertStmt(&Object{})
-	_, err = tx.NamedExecContext(ctx, stmt, object)
+	stmt, _ := db.BuildUpsertStmt(&Object{})
+	_, err = tx.NamedExecContext(ctx, stmt, newObject)
 	if err != nil {
 		return nil, fmt.Errorf("failed to insert object: %w", err)
 	}
 
-	stmt, _ = object.db.BuildUpsertStmt(&IdTagRow{})
-	_, err = tx.NamedExecContext(ctx, stmt, mapToTagRows(object.ID, ev.Tags))
+	stmt, _ = db.BuildUpsertStmt(&IdTagRow{})
+	_, err = tx.NamedExecContext(ctx, stmt, mapToTagRows(newObject.ID, ev.Tags))
 	if err != nil {
 		return nil, fmt.Errorf("failed to upsert object id tags: %w", err)
 	}
 
-	extraTag := &ExtraTagRow{ObjectId: object.ID}
+	extraTag := &ExtraTagRow{ObjectId: newObject.ID}
 	_, err = tx.NamedExecContext(ctx, `DELETE FROM "object_extra_tag" WHERE "object_id" = :object_id`, extraTag)
 	if err != nil {
 		return nil, fmt.Errorf("failed to delete object extra tags: %w", err)
 	}
 
 	if len(ev.ExtraTags) > 0 {
-		stmt, _ := object.db.BuildInsertStmt(extraTag)
-		_, err = tx.NamedExecContext(ctx, stmt, mapToTagRows(object.ID, ev.ExtraTags))
+		stmt, _ := db.BuildInsertStmt(extraTag)
+		_, err = tx.NamedExecContext(ctx, stmt, mapToTagRows(newObject.ID, ev.ExtraTags))
 		if err != nil {
 			return nil, fmt.Errorf("failed to insert object extra tags: %w", err)
 		}
@@ -163,9 +169,12 @@ func FromEvent(ctx context.Context, db *database.DB, ev *event.Event) (*Object,
 		return nil, fmt.Errorf("can't commit object database transaction: %w", err)
 	}
 
-	object.ExtraTags = ev.ExtraTags
-	object.Name = ev.Name
-	object.URL = utils.ToDBString(ev.URL)
+	if !objectExists {
+		cache[id.String()] = newObject
+		return newObject, nil
+	}
+
+	*object = *newObject
 
 	return object, nil
 }