Ticket #39223: 39223.1.diff

wp-includes/ms-functions.php

@@ -720 +720 @@
         $user = preg_replace( '/\s+/', '', sanitize_user( $user, true ) );
         $user_email = sanitize_email( $user_email );
         $key = substr( md5( time() . rand() . $user_email ), 0, 16 );
-        $meta = serialize($meta);
+
+        /**
+         * Allow plugins to edit $meta array
+         *
+         * @since 4.8.0
+         *
+         * @param array  $meta       Additional signup meta. By default, this is an empty array.
+         * @param string $user       The user's requested login name.
+         * @param string $user_email The user's email address.
+         * @param string $key        The user's activation key
+         */
+        $meta = apply_filters( 'signup_user_meta', $meta, $user, $user_email, $key );
 
         $wpdb->insert( $wpdb->signups, array(
                 'domain' => '',
@@ -730 +741 @@
                 'user_email' => $user_email,
                 'registered' => current_time('mysql', true),
                 'activation_key' => $key,
-                'meta' => $meta
+                'meta' => serialize( $meta ),
         ) );
 
         /**