Use link host to find external links

tildes/static/js/behaviors/external-links-new-tabs.js

@@ -1,17 +1,8 @@
 $.onmount('[data-js-external-links-new-tabs]', function() {
-    /* Open external links in topic, comment, and message text in
-     * new tabs.
-     *
-     * The regex matches links starting with "/" or "tildes.net", which are
-     * "internal" links to Tildes pages (posts, topics, users, etc). All
-     * other links are considered "external" and open in a new tab.
-     */
-    let re = /^((?!\/).)$|^https?:\/\/((?!tildes\.net).).*$/gm;
-    // Loop through links
+    // Open external links in topic, comment, and message text in new tabs
     $(this).find('a').each(function() {
-        // Check if href is external
-        if (re.exec(this.href) !== null) {
-            $(this).attr('target', '_blank');
+        if (this.host !== window.location.host) {
+          $(this).attr('target', '_blank');
         }
     });
 });