From 74a7f96cc2fc97952cb931970934b07a164fca31 Mon Sep 17 00:00:00 2001
From: Hazelnoot <acomputerdog@gmail.com>
Date: Thu, 18 Sep 2025 13:07:07 -0400
Subject: [PATCH] prevent remote instances from renoting a boost

---
 packages/backend/src/core/NoteCreateService.ts            | 5 +++++
 packages/backend/src/core/NoteEditService.ts              | 5 +++++
 packages/backend/src/server/api/endpoints/notes/create.ts | 2 ++
 packages/backend/src/server/api/endpoints/notes/edit.ts   | 4 ++--
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index ea74d3a84e..a3079d9db9 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -57,6 +57,7 @@ import { IdentifiableError } from '@/misc/identifiable-error.js';
 import { LatestNoteService } from '@/core/LatestNoteService.js';
 import { CollapsedQueue } from '@/misc/collapsed-queue.js';
 import { CacheService } from '@/core/CacheService.js';
+import { isPureRenote } from '@/misc/is-renote.js';
 
 type NotificationType = 'reply' | 'renote' | 'quote' | 'mention';
 
@@ -284,6 +285,10 @@ export class NoteCreateService implements OnApplicationShutdown {
 		}
 
 		if (data.renote) {
+			if (isPureRenote(data.renote)) {
+				throw new IdentifiableError('fd4cc33e-2a37-48dd-99cc-9b806eb2031a', 'Cannot renote a pure renote (boost)');
+			}
+
 			switch (data.renote.visibility) {
 				case 'public':
 					// public noteは無条件にrenote可能
diff --git a/packages/backend/src/core/NoteEditService.ts b/packages/backend/src/core/NoteEditService.ts
index f31b267ad8..d96a835b8a 100644
--- a/packages/backend/src/core/NoteEditService.ts
+++ b/packages/backend/src/core/NoteEditService.ts
@@ -52,6 +52,7 @@ import { IdentifiableError } from '@/misc/identifiable-error.js';
 import { LatestNoteService } from '@/core/LatestNoteService.js';
 import { CollapsedQueue } from '@/misc/collapsed-queue.js';
 import { NoteCreateService } from '@/core/NoteCreateService.js';
+import { isPureRenote } from '@/misc/is-renote.js';
 
 type NotificationType = 'reply' | 'renote' | 'quote' | 'mention' | 'edited';
 
@@ -303,6 +304,10 @@ export class NoteEditService implements OnApplicationShutdown {
 		}
 
 		if (this.isRenote(data)) {
+			if (isPureRenote(data.renote)) {
+				throw new IdentifiableError('fd4cc33e-2a37-48dd-99cc-9b806eb2031a', 'Cannot renote a pure renote (boost)');
+			}
+
 			// Check for recursion
 			let renoteId: string | null = data.renote.id;
 			while (renoteId) {
diff --git a/packages/backend/src/server/api/endpoints/notes/create.ts b/packages/backend/src/server/api/endpoints/notes/create.ts
index d6fccd1b84..98bf827d25 100644
--- a/packages/backend/src/server/api/endpoints/notes/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/create.ts
@@ -428,6 +428,8 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 						throw new ApiError(meta.errors.containsTooManyMentions);
 					} else if (e.id === '1c0ea108-d1e3-4e8e-aa3f-4d2487626153') {
 						throw new ApiError(meta.errors.quoteDisabledForUser);
+					} else if (e.id === 'fd4cc33e-2a37-48dd-99cc-9b806eb2031a') {
+						throw new ApiError(meta.errors.cannotReRenote);
 					}
 				}
 				throw e;
diff --git a/packages/backend/src/server/api/endpoints/notes/edit.ts b/packages/backend/src/server/api/endpoints/notes/edit.ts
index 08d5d0daac..8a65e016d5 100644
--- a/packages/backend/src/server/api/endpoints/notes/edit.ts
+++ b/packages/backend/src/server/api/endpoints/notes/edit.ts
@@ -358,8 +358,6 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 				if (renote == null) {
 					throw new ApiError(meta.errors.noSuchRenoteTarget);
-				} else if (isRenote(renote) && !isQuote(renote)) {
-					throw new ApiError(meta.errors.cannotReRenote);
 				}
 
 				// Check blocking
@@ -481,6 +479,8 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 						throw new ApiError(meta.errors.quoteDisabledForUser);
 					} else if (e.id === 'ea93b7c2-3d6c-4e10-946b-00d50b1a75cb') {
 						throw new ApiError(meta.errors.cannotQuoteaQuoteOfCurrentPost);
+					} else if (e.id === 'fd4cc33e-2a37-48dd-99cc-9b806eb2031a') {
+						throw new ApiError(meta.errors.cannotReRenote);
 					}
 				}
 				throw e;