MDL-57775 xmlrpc: Pass escaping to xmlrpc_encode_request() calls

This patch adds the missing 'escaping' option to all remaining
xmlrpc_encode_request() calls in the moodle core code.

Without this, the xmlrpc_decode_request() call on the server side may
lead to wrongly decoded non-ascii characters.

mnet/lib.php

@@ -56,7 +56,10 @@ function mnet_get_public_key($uri, $application=null) {
         $application = $DB->get_record('mnet_application', array('name'=>'moodle'));
     }
 
-    $rq = xmlrpc_encode_request('system/keyswap', array($CFG->wwwroot, $mnet->public_key, $application->name), array("encoding" => "utf-8"));
+    $rq = xmlrpc_encode_request('system/keyswap', array($CFG->wwwroot, $mnet->public_key, $application->name), array(
+        'encoding' => 'utf-8',
+        'escaping' => 'markup',
+    ));
     $ch = curl_init($uri . $application->xmlrpc_server_url);
 
     curl_setopt($ch, CURLOPT_TIMEOUT, 60);

webservice/xmlrpc/lib.php

@@ -75,7 +75,8 @@ class webservice_xmlrpc_client {
 
         // Set output options.
         $outputoptions = array(
-            'encoding' => 'utf-8'
+            'encoding' => 'utf-8',
+            'escaping' => 'markup',
         );
 
         // Encode the request.