Ticket #46992: 46992.diff

src/wp-includes/rest-api/class-wp-rest-server.php

@@ -1266 +1266 @@
          * @param array $headers Map of header name to header value.
          */
         public function send_headers( $headers ) {
+                /**
+                 * Filters the HTTP headers before they're sent to the browser for a REST request.
+                 *
+                 * @since 5.2.0
+                 *
+                 * @param string[] $headers Associative array of headers to be sent.
+                 */
+                $headers = apply_filters( 'wp_rest_headers', $headers );
+
                 foreach ( $headers as $key => $value ) {
                         $this->send_header( $key, $value );
                 }