server: able to store remote thread IDs

packages/backend/migration/1667212446191-remote-thread-ids.js

@@ -0,0 +1,17 @@
+import config from '../built/config/index.js';
+
+export class remoteThreadIds1667212446191 {
+	name = 'remoteThreadIds1667212446191';
+
+	async up(queryRunner) {
+		await Promise.all([
+			queryRunner.query(`UPDATE "note" SET "threadId" = '${config.url}/notes/' + "threadId"`),
+			queryRunner.query(`UPDATE "note_thread_muting" SET "threadId" = '${config.url}/notes/' + "threadId"`),
+		]);
+	}
+
+	async down() {
+		// cannot be undone:
+		// after this migration other instances threadIds may be stored in the database
+	}
+}

packages/backend/src/remote/activitypub/renderer/note.ts

@@ -131,7 +131,7 @@ export default async function renderNote(note: Note, dive = true, isTalk = false
 
 	return {
 		id: `${config.url}/notes/${note.id}`,
-		context: `${config.url}/notes/${note.threadId}`,
+		context: note.threadId,
 		type: 'Note',
 		attributedTo,
 		summary,

packages/backend/src/services/note/create.ts

@@ -509,7 +509,7 @@ async function insertNote(user: { id: User['id']; host: User['host']; }, data: O
 		replyId: data.reply ? data.reply.id : null,
 		renoteId: data.renote ? data.renote.id : null,
 		channelId: data.channel ? data.channel.id : null,
-		threadId: data.reply?.threadId ?? id,
+		threadId: data.reply?.threadId ?? `${config.url}/notes/${id}`,
 		name: data.name,
 		text: data.text,
 		hasPoll: data.poll != null,