Fix context popup error

Author: wxiaoguang

web_src/js/features/contextpopup.js

@@ -10,7 +10,15 @@ export default function initContextPopups() {
     if ($(this).hasClass('ref-external-issue')) {
       return;
     }
-    const [index, _issues, repo, owner] = $(this).attr('href').replace(/[#?].*$/, '').split('/').reverse();
+
+    // some links were not generated by us and may lack the href attribute
+    const href = $(this).attr('href');
+    if (!href) return;
+    // again, a simple check to make sure the link href is likely generated by us
+    const fields = href.replace(/[#?].*$/, '').split('/');
+    if (fields.length !== 4) return;
+
+    const [owner, repo, _issues, index] = fields;
 
     const el = document.createElement('div');
     el.className = 'ui custom popup hidden';