fix(backend): handle relay-delivered Announce activities correctly (#17308)

* fix(backend): handle relay-delivered Announce activities correctly

Relay Announce activities now use the target note URI instead of the
Announce URI for federation allowlist checks, dedup locking, and
existence lookups. Notes delivered via relay are published directly to
the notes stream without creating a renote.

Closes #11056

* Update packages/backend/src/core/RelayService.ts

Co-authored-by: syuilo <4439005+syuilo@users.noreply.github.com>

---------

Co-authored-by: かっこかり <67428053+kakkokari-gtyih@users.noreply.github.com>
Co-authored-by: syuilo <4439005+syuilo@users.noreply.github.com>

CHANGELOG.md

@@ -16,6 +16,7 @@
 - Fix: ローカルに存在しないリモートアカウントに対するアカウント削除リクエストを受信した際に、そのユーザーを新規作成して削除する挙動を修正
 - Fix: Inboxでの特定のエラーによる失敗はDelayedにしない
 - Fix: ID生成アルゴリズムにULIDを使用している場合にMisskeyが正しく動作しない問題を修正
+- Fix: リレー経由で届いたノートがリノートとして表示される問題を修正
 - Fix: robots.txtの内容を調整
 
 ## 2026.3.2

packages/backend/src/core/RelayService.ts

@@ -91,13 +91,27 @@ export class RelayService {
 		return JSON.stringify(result);
 	}
 
+	@bindThis
+	private getAcceptedRelays(): Promise<MiRelay[]> {
+		return this.relaysCache.fetch(() => this.relaysRepository.findBy({
+			status: 'accepted',
+		}));
+	}
+
+	@bindThis
+	public async isRelayActor(actor: { inbox: string | null; sharedInbox: string | null }): Promise<boolean> {
+		const relays = await this.getAcceptedRelays();
+		return relays.some(relay =>
+			(actor.inbox != null && relay.inbox === actor.inbox)
+			|| (actor.sharedInbox != null && relay.inbox === actor.sharedInbox),
+		);
+	}
+
 	@bindThis
 	public async deliverToRelays(user: { id: MiUser['id']; host: null; }, activity: any): Promise<void> {
 		if (activity == null) return;
 
-		const relays = await this.relaysCache.fetch(() => this.relaysRepository.findBy({
-			status: 'accepted',
-		}));
+		const relays = await this.getAcceptedRelays();
 		if (relays.length === 0) return;
 
 		const copy = deepClone(activity);

packages/backend/src/core/activitypub/ApInboxService.ts

@@ -302,12 +302,14 @@ export class ApInboxService {
 
 	@bindThis
 	private async announceNote(actor: MiRemoteUser, activity: IAnnounce, target: IPost, resolver?: Resolver): Promise<string | void> {
-		const uri = getApId(activity);
-
 		if (actor.isSuspended) {
 			return;
 		}
 
+		// リレーからのAnnounceかチェック
+		const fromRelay = await this.relayService.isRelayActor(actor);
+		const uri = getApId(fromRelay ? target : activity);
+
 		// アナウンス先が許可されているかチェック
 		if (!this.utilityService.isFederationAllowedUri(uri)) return;
 
@@ -336,6 +338,14 @@ export class ApInboxService {
 				throw err;
 			}
 
+			// リレーからのAnnounceはリノートを作成せず、ノートを直接公開する
+			if (fromRelay) {
+				this.logger.info(`Publishing relay-delivered note: ${uri}`);
+				const noteObj = await this.noteEntityService.pack(renote, null, { skipHide: true, withReactionAndUserPairCache: true });
+				this.globalEventService.publishNotesStream(noteObj);
+				return;
+			}
+
 			if (!await this.noteEntityService.isVisibleForMe(renote, actor.id)) {
 				return 'skip: invalid actor for this activity';
 			}