Ticket #41672: 41672-rest-user-conflict-409.patch

wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php

@@ -513 +513 @@
 
                 $user_id = wp_insert_user( wp_slash( (array) $prepared_user ) );
 
-                if ( is_wp_error( $user_id ) ) {
-                        return $user_id;
+                if ( is_wp_error( $user_id ) ) {
+                        $error_code = $user_id->get_error_code();
+
+                        if ( in_array( $error_code, array( 'existing_user_email', 'existing_user_login' ), true ) ) {
+                                $user_id->add_data(
+                                        array( 'status' => 409 ),
+                                        $error_code
+                                );
+                        }
+
+                        return $user_id;
                 }
 
                 $user = get_user_by( 'id', $user_id );