fix note hiding when renote and target have different visibility settings

packages/backend/src/core/entities/NoteEntityService.ts

@@ -16,6 +16,7 @@ import { bindThis } from '@/decorators.js';
 import { DebounceLoader } from '@/misc/loader.js';
 import { IdService } from '@/core/IdService.js';
 import { ReactionsBufferingService } from '@/core/ReactionsBufferingService.js';
+import { isPureRenotePacked } from '@/misc/is-renote.js';
 import type { OnModuleInit } from '@nestjs/common';
 import type { CacheService } from '../CacheService.js';
 import type { CustomEmojiService } from '../CustomEmojiService.js';
@@ -122,29 +123,26 @@ export class NoteEntityService implements OnModuleInit {
 			} else if (packedNote.renote && (meId === packedNote.renote.userId)) {
 				hide = false;
 			} else {
-				if (packedNote.renote) {
-					const isFollowing = await this.followingsRepository.exists({
-						where: {
-							followeeId: packedNote.renote.userId,
-							followerId: meId,
-						},
-					});
+				// フォロワーかどうか
+				const isFollowing = await this.followingsRepository.exists({
+					where: {
+						followeeId: packedNote.userId,
+						followerId: meId,
+					},
+				});
 
-					hide = !isFollowing;
-				} else {
-					// フォロワーかどうか
-					const isFollowing = await this.followingsRepository.exists({
-						where: {
-							followeeId: packedNote.userId,
-							followerId: meId,
-						},
-					});
-
-					hide = !isFollowing;
-				}
+				hide = !isFollowing;
 			}
 		}
 
+		// If this is a pure renote (boost), then we should *also* check the boosted note's visibility.
+		// Otherwise we can have empty notes on the timeline, which is not good.
+		// Notes are packed in depth-first order, so we can safely grab the "isHidden" property to avoid duplicated checks.
+		// This is pulled out to ensure that we check both the renote *and* the boosted note.
+		if (packedNote.renote?.isHidden && isPureRenotePacked(packedNote)) {
+			hide = true;
+		}
+
 		if (!hide && meId && packedNote.userId !== meId) {
 			const isBlocked = (await this.cacheService.userBlockedCache.fetch(meId)).has(packedNote.userId);