From af6ae6ee8a24397007a0d51f5803059b95f5f64b Mon Sep 17 00:00:00 2001
From: Julian Lam <julian@nodebb.org>
Date: Fri, 5 Jul 2024 15:50:14 -0400
Subject: [PATCH] fix: send back empty array if no direct replies, bug with
 reply generation

---
 src/activitypub/mocks.js              |  5 ++++-
 src/controllers/activitypub/actors.js | 12 +++++++++---
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/activitypub/mocks.js b/src/activitypub/mocks.js
index 7e9051d74d..7df1091204 100644
--- a/src/activitypub/mocks.js
+++ b/src/activitypub/mocks.js
@@ -5,6 +5,7 @@ const mime = require('mime');
 const path = require('path');
 const sanitize = require('sanitize-html');
 
+const db = require('../database');
 const meta = require('../meta');
 const user = require('../user');
 const categories = require('../categories');
@@ -384,6 +385,8 @@ Mocks.note = async (post) => {
 		return payload;
 	});
 
+	const replyCount = await db.sortedSetCard(`pid:${post.pid}:replies`);
+
 	const object = {
 		'@context': 'https://www.w3.org/ns/activitystreams',
 		id,
@@ -403,7 +406,7 @@ Mocks.note = async (post) => {
 		source,
 		tag,
 		attachment,
-		replies: `${id}/replies`,
+		replies: replyCount > 0 ? `${id}/replies` : [],
 	};
 
 	return object;
diff --git a/src/controllers/activitypub/actors.js b/src/controllers/activitypub/actors.js
index 8fe89f38e5..4c9326eb09 100644
--- a/src/controllers/activitypub/actors.js
+++ b/src/controllers/activitypub/actors.js
@@ -63,6 +63,12 @@ Actors.note = async function (req, res) {
 };
 
 Actors.replies = async function (req, res) {
+	const allowed = utils.isNumber(req.params.pid) && await privileges.posts.can('topics:read', req.params.pid, activitypub._constants.uid);
+	const exists = await posts.exists(req.params.pid);
+	if (!allowed || !exists) {
+		return res.sendStatus(404);
+	}
+
 	const page = parseInt(req.query.page, 10);
 	const replies = await activitypub.helpers.generateCollection({
 		set: `pid:${req.params.pid}:replies`,
@@ -71,6 +77,9 @@ Actors.replies = async function (req, res) {
 		url: `${nconf.get('url')}/post/${req.params.pid}/replies`,
 	});
 
+	// Convert pids to urls
+	replies.orderedItems = replies.orderedItems.map(pid => (utils.isNumber(pid) ? `${nconf.get('url')}/post/${pid}` : pid));
+
 	const object = {
 		'@context': 'https://www.w3.org/ns/activitystreams',
 		id: `${nconf.get('url')}/post/${req.params.pid}/replies${replies.orderedItems && page ? `?page=${page}` : ''}`,
@@ -78,9 +87,6 @@ Actors.replies = async function (req, res) {
 		...replies,
 	}
 
-	// Convert pids to urls
-	replies.orderedItems = replies.orderedItems.map(pid => (utils.isNumber(pid) ? `${nconf.get('url')}/post/${pid}` : pid));
-
 	res.status(200).json(object);
 };