From bdda467ae18083f56573ea454468a5bbd26c2df0 Mon Sep 17 00:00:00 2001
From: Toby Zerner <toby.zerner@gmail.com>
Date: Tue, 4 Dec 2018 09:23:11 +1030
Subject: [PATCH] Prevent crash if likes relationship hasn't been loaded

This could theoretically happen if a post is loaded in some other context
(without its likes relationship) and overwrites the full version in the
store. While this should ideally never happen, it's better to fail
gracefully if it does.

Fixes flarum/core#1665
---
 extensions/likes/js/src/forum/addLikeAction.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/extensions/likes/js/src/forum/addLikeAction.js b/extensions/likes/js/src/forum/addLikeAction.js
index 3aa17f204..a1ac07c60 100644
--- a/extensions/likes/js/src/forum/addLikeAction.js
+++ b/extensions/likes/js/src/forum/addLikeAction.js
@@ -9,7 +9,9 @@ export default function() {
 
     if (post.isHidden() || !post.canLike()) return;
 
-    let isLiked = app.session.user && post.likes().some(user => user === app.session.user);
+    const likes = post.likes();
+
+    let isLiked = app.session.user && likes && likes.some(user => user === app.session.user);
 
     items.add('like',
       Button.component({