External Libraries: Upgrade PHPMailer to version 6.5.3.

The latest release includes official PHP 8.1 support, as well as some small bug fixes, including one for PHP 5.6 cross-version support.

Release notes:
* https://github.com/PHPMailer/PHPMailer/releases/tag/v6.5.2
* https://github.com/PHPMailer/PHPMailer/releases/tag/v6.5.3

For a full list of changes in this update, see the PHPMailer GitHub:
https://github.com/PHPMailer/PHPMailer/compare/v6.5.1...v6.5.3

Follow-up to [50628], [50799], [51169], [51634], [51635].

Props jrf, Synchro.
Fixes #54514.
Built from https://develop.svn.wordpress.org/trunk@52252


git-svn-id: http://core.svn.wordpress.org/trunk@51844 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/PHPMailer/PHPMailer.php

@@ -750,7 +750,7 @@ class PHPMailer
      *
      * @var string
      */
-    const VERSION = '6.5.1';
+    const VERSION = '6.5.3';
 
     /**
      * Error severity: message only, continue processing.
@@ -1451,7 +1451,12 @@ class PHPMailer
                 $errorcode = 0;
                 if (defined('INTL_IDNA_VARIANT_UTS46')) {
                     //Use the current punycode standard (appeared in PHP 7.2)
-                    $punycode = idn_to_ascii($domain, $errorcode, \INTL_IDNA_VARIANT_UTS46);
+                    $punycode = idn_to_ascii(
+                        $domain,
+                        \IDNA_DEFAULT | \IDNA_USE_STD3_RULES | \IDNA_CHECK_BIDI |
+                            \IDNA_CHECK_CONTEXTJ | \IDNA_NONTRANSITIONAL_TO_ASCII,
+                        \INTL_IDNA_VARIANT_UTS46
+                    );
                 } elseif (defined('INTL_IDNA_VARIANT_2003')) {
                     //Fall back to this old, deprecated/removed encoding
                     // phpcs:ignore PHPCompatibility.Constants.RemovedConstants.intl_idna_variant_2003Deprecated
@@ -1699,7 +1704,10 @@ class PHPMailer
         //Sendmail docs: http://www.sendmail.org/~ca/email/man/sendmail.html
         //Qmail docs: http://www.qmail.org/man/man8/qmail-inject.html
         //Example problem: https://www.drupal.org/node/1057954
-        if (empty($this->Sender) && !empty(ini_get('sendmail_from'))) {
+
+        //PHP 5.6 workaround
+        $sendmail_from_value = ini_get('sendmail_from');
+        if (empty($this->Sender) && !empty($sendmail_from_value)) {
             //PHP config has a sender address we can use
             $this->Sender = ini_get('sendmail_from');
         }
@@ -1881,7 +1889,10 @@ class PHPMailer
         //Qmail docs: http://www.qmail.org/man/man8/qmail-inject.html
         //Example problem: https://www.drupal.org/node/1057954
         //CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
-        if (empty($this->Sender) && !empty(ini_get('sendmail_from'))) {
+
+        //PHP 5.6 workaround
+        $sendmail_from_value = ini_get('sendmail_from');
+        if (empty($this->Sender) && !empty($sendmail_from_value)) {
             //PHP config has a sender address we can use
             $this->Sender = ini_get('sendmail_from');
         }
@@ -2198,7 +2209,7 @@ class PHPMailer
      * @param string $langcode  ISO 639-1 2-character language code (e.g. French is "fr")
      *                          Optionally, the language code can be enhanced with a 4-character
      *                          script annotation and/or a 2-character country annotation.
-     * @param string $lang_path Path to the language file directory, with trailing separator (slash).D
+     * @param string $lang_path Path to the language file directory, with trailing separator (slash)
      *                          Do not set this from user input!
      *
      * @return bool Returns true if the requested language was loaded, false otherwise.

wp-includes/PHPMailer/SMTP.php

@@ -35,7 +35,7 @@ class SMTP
      *
      * @var string
      */
-    const VERSION = '6.5.1';
+    const VERSION = '6.5.3';
 
     /**
      * SMTP line break constant.
@@ -392,7 +392,6 @@ class SMTP
                 STREAM_CLIENT_CONNECT,
                 $socket_context
             );
-            restore_error_handler();
         } else {
             //Fall back to fsockopen which should work in more places, but is missing some features
             $this->edebug(
@@ -407,8 +406,8 @@ class SMTP
                 $errstr,
                 $timeout
             );
-            restore_error_handler();
         }
+        restore_error_handler();
 
         //Verify we connected properly
         if (!is_resource($connection)) {
@@ -696,7 +695,7 @@ class SMTP
     /**
      * Send an SMTP DATA command.
      * Issues a data command and sends the msg_data to the server,
-     * finializing the mail transaction. $msg_data is the message
+     * finalizing the mail transaction. $msg_data is the message
      * that is to be send with the headers. Each header needs to be
      * on a single line followed by a <CRLF> with the message headers
      * and the message body being separated by an additional <CRLF>.
@@ -1170,7 +1169,7 @@ class SMTP
         if (!$this->server_caps) {
             $this->setError('No HELO/EHLO was sent');
 
-            return;
+            return null;
         }
 
         if (!array_key_exists($name, $this->server_caps)) {
@@ -1182,7 +1181,7 @@ class SMTP
             }
             $this->setError('HELO handshake was used; No information about server extensions available');
 
-            return;
+            return null;
         }
 
         return $this->server_caps[$name];

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-52251';
+$wp_version = '5.9-alpha-52252';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.