Ticket #32684: 32684.patch

src/wp-includes/user.php

@@ -2158 +2158 @@
                 $send_pass_change_email = apply_filters( 'send_pass_change_email', true, $user, $userdata );
         }
 
-        if ( $user['user_email'] !== $userdata['user_email'] ) {
+        if ( isset( $userdata['user_email'] ) && $user['user_email'] !== $userdata['user_email'] ) {
                 /**
                  * Filter to stop the sending of the email change email.
                  *