Issue #3442833: Undefined array key warning in UrlHelper::parse()

Closes #3442833

core/lib/Drupal/Component/Utility/UrlHelper.php

@@ -200,9 +200,10 @@ public static function parse($url) {
     // appears in front of the '?' query argument delimiter.
     $scheme_delimiter_position = strpos($url, '://');
     $query_delimiter_position = strpos($url, '?');
-    if ($scheme_delimiter_position !== FALSE && ($query_delimiter_position === FALSE || $scheme_delimiter_position < $query_delimiter_position)) {
+    $fragment_delimiter_position = strpos($url, '#');
+    if ($scheme_delimiter_position !== FALSE && ($query_delimiter_position === FALSE || $scheme_delimiter_position < $query_delimiter_position) && ($fragment_delimiter_position === FALSE || $scheme_delimiter_position < $fragment_delimiter_position)) {
       // Split off the fragment, if any.
-      if (str_contains($url, '#')) {
+      if ($fragment_delimiter_position !== FALSE) {
         [$url, $options['fragment']] = explode('#', $url, 2);
       }