From 9dc0d849ecd827b4241e462fed7a94d6d0be5563 Mon Sep 17 00:00:00 2001
From: Hazelnoot <acomputerdog@gmail.com>
Date: Thu, 18 Sep 2025 12:24:40 -0400
Subject: [PATCH] recurse when preventing quote chains

---
 packages/backend/src/core/NoteEditService.ts         | 12 ++++++++++--
 .../backend/src/server/api/endpoints/notes/edit.ts   |  6 ++----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/packages/backend/src/core/NoteEditService.ts b/packages/backend/src/core/NoteEditService.ts
index 9e8bb8b4fd..f31b267ad8 100644
--- a/packages/backend/src/core/NoteEditService.ts
+++ b/packages/backend/src/core/NoteEditService.ts
@@ -303,8 +303,16 @@ export class NoteEditService implements OnApplicationShutdown {
 		}
 
 		if (this.isRenote(data)) {
-			if (data.renote.id === oldnote.id) {
-				throw new IdentifiableError('ea93b7c2-3d6c-4e10-946b-00d50b1a75cb', `edit failed for ${oldnote.id}: cannot renote itself`);
+			// Check for recursion
+			let renoteId: string | null = data.renote.id;
+			while (renoteId) {
+				if (renoteId === oldnote.id) {
+					throw new IdentifiableError('ea93b7c2-3d6c-4e10-946b-00d50b1a75cb', `edit failed for ${oldnote.id}: cannot renote itself`);
+				}
+
+				// TODO create something like threadId but for quotes, that way we don't need full recursion
+				const next = await this.notesRepository.findOne({ where: { id: renoteId }, select: { renoteId: true } });
+				renoteId = next?.renoteId ?? null;
 			}
 
 			switch (data.renote.visibility) {
diff --git a/packages/backend/src/server/api/endpoints/notes/edit.ts b/packages/backend/src/server/api/endpoints/notes/edit.ts
index 717dab59e1..08d5d0daac 100644
--- a/packages/backend/src/server/api/endpoints/notes/edit.ts
+++ b/packages/backend/src/server/api/endpoints/notes/edit.ts
@@ -362,10 +362,6 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 					throw new ApiError(meta.errors.cannotReRenote);
 				}
 
-				if (renote.renoteId === ps.editId) {
-					throw new ApiError(meta.errors.cannotQuoteaQuoteOfCurrentPost);
-				}
-
 				// Check blocking
 				if (renote.userId !== me.id) {
 					const blockExist = await this.blockingsRepository.exists({
@@ -483,6 +479,8 @@ 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 === 'ea93b7c2-3d6c-4e10-946b-00d50b1a75cb') {
+						throw new ApiError(meta.errors.cannotQuoteaQuoteOfCurrentPost);
 					}
 				}
 				throw e;