diff --git a/lib/webdavlib.php b/lib/webdavlib.php
index ea4493aa6fa..bbd3d1b3baa 100644
--- a/lib/webdavlib.php
+++ b/lib/webdavlib.php
@@ -197,7 +197,10 @@ class webdav_client {
     function close() {
         $this->_error_log('closing socket ' . $this->sock);
         $this->_connection_closed = true;
-        fclose($this->sock);
+        if (is_resource($this->sock)) {
+            // Only close the socket if it is a resource.
+            fclose($this->sock);
+        }
     }
 
     /**
@@ -640,7 +643,7 @@ class webdav_client {
                     if (strcmp($response['header']['Content-Type'], 'text/xml; charset="utf-8"') == 0) {
                         // ok let's get the content of the xml stuff
                         $this->_parser = xml_parser_create_ns();
-                        $this->_parserid = (int) $this->_parser;
+                        $this->_parserid = $this->get_parser_id($this->_parser);
                         // forget old data...
                         unset($this->_lock[$this->_parserid]);
                         unset($this->_xmltree[$this->_parserid]);
@@ -738,7 +741,7 @@ class webdav_client {
                     if (strcmp($response['header']['Content-Type'], 'text/xml; charset="utf-8"') == 0) {
                         // ok let's get the content of the xml stuff
                         $this->_parser = xml_parser_create_ns();
-                        $this->_parserid = (int) $this->_parser;
+                        $this->_parserid = $this->get_parser_id($this->_parser);
                         // forget old data...
                         unset($this->_delete[$this->_parserid]);
                         unset($this->_xmltree[$this->_parserid]);
@@ -830,7 +833,7 @@ EOD;
                     if (preg_match('#(application|text)/xml;\s?charset=[\'\"]?utf-8[\'\"]?#i', $response['header']['Content-Type'])) {
                         // ok let's get the content of the xml stuff
                         $this->_parser = xml_parser_create_ns('UTF-8');
-                        $this->_parserid = (int) $this->_parser;
+                        $this->_parserid = $this->get_parser_id($this->_parser);
                         // forget old data...
                         unset($this->_ls[$this->_parserid]);
                         unset($this->_xmltree[$this->_parserid]);
@@ -1069,7 +1072,7 @@ EOD;
 
     private function _endElement($parser, $name) {
         // end tag was found...
-        $parserid = (int) $parser;
+        $parserid = $this->get_parser_id($parser);
         $this->_xmltree[$parserid] = substr($this->_xmltree[$parserid],0, strlen($this->_xmltree[$parserid]) - (strlen($name) + 1));
     }
 
@@ -1085,7 +1088,7 @@ EOD;
      */
     private function _propfind_startElement($parser, $name, $attrs) {
         // lower XML Names... maybe break a RFC, don't know ...
-        $parserid = (int) $parser;
+        $parserid = $this->get_parser_id($parser);
 
         $propname = strtolower($name);
         if (!empty($this->_xmltree[$parserid])) {
@@ -1181,7 +1184,7 @@ EOD;
      */
     private function _delete_startElement($parser, $name, $attrs) {
         // lower XML Names... maybe break a RFC, don't know ...
-        $parserid = (int) $parser;
+        $parserid = $this->get_parser_id($parser);
         $propname = strtolower($name);
         $this->_xmltree[$parserid] .= $propname . '_';
 
@@ -1233,7 +1236,7 @@ EOD;
      */
     private function _lock_startElement($parser, $name, $attrs) {
         // lower XML Names... maybe break a RFC, don't know ...
-        $parserid = (int) $parser;
+        $parserid = $this->get_parser_id($parser);
         $propname = strtolower($name);
         $this->_xmltree[$parserid] .= $propname . '_';
 
@@ -1289,7 +1292,7 @@ EOD;
      * @access private
      */
     private function _lock_cData($parser, $cdata) {
-        $parserid = (int) $parser;
+        $parserid = $this->get_parser_id($parser);
         if (trim($cdata) <> '') {
             // $this->_error_log(($this->_xmltree[$parserid]) . '='. htmlentities($cdata));
             $this->_lock_ref_cdata .= $cdata;
@@ -1747,4 +1750,18 @@ EOD;
             error_log($err_string);
         }
     }
+
+    /**
+     * Helper method to get the parser id for both PHP 7 and 8.
+     *
+     * @param resource|object $parser
+     * @return int
+     */
+    private function get_parser_id($parser): int {
+        if (is_object($parser)) {
+            return spl_object_id($parser);
+        } else {
+            return (int) $parser;
+        }
+    }
 }