From 450984abf3b76761e9a2c56ed1cba53f9cf4fbbb Mon Sep 17 00:00:00 2001
From: eight <eight04@gmail.com>
Date: Mon, 9 Sep 2019 12:48:44 +0800
Subject: [PATCH] Fix: don't assign undefined to style object (#764)

---
 js/usercss.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/js/usercss.js b/js/usercss.js
index deebcbbb..85937ec6 100644
--- a/js/usercss.js
+++ b/js/usercss.js
@@ -43,7 +43,9 @@ const usercss = (() => {
         style.usercssData = metadata;
         // https://github.com/openstyles/stylus/issues/560#issuecomment-440561196
         for (const [key, value] of Object.entries(GLOBAL_METAS)) {
-          style[value || key] = metadata[key];
+          if (metadata[key] !== undefined) {
+            style[value || key] = metadata[key];
+          }
         }
         return style;
       });