diff -r be944660c56a -r 3d72ae0968f4 wp/wp-includes/blocks/pattern.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/blocks/pattern.php	Tue Sep 27 16:37:53 2022 +0200
@@ -0,0 +1,44 @@
+<?php
+/**
+ * Server-side rendering of the `core/pattern` block.
+ *
+ * @package WordPress
+ */
+
+/**
+ *  Registers the `core/pattern` block on the server.
+ *
+ * @return void
+ */
+function register_block_core_pattern() {
+	register_block_type_from_metadata(
+		__DIR__ . '/pattern',
+		array(
+			'render_callback' => 'render_block_core_pattern',
+		)
+	);
+}
+
+/**
+ * Renders the `core/pattern` block on the server.
+ *
+ * @param array $attributes Block attributes.
+ *
+ * @return string Returns the output of the pattern.
+ */
+function render_block_core_pattern( $attributes ) {
+	if ( empty( $attributes['slug'] ) ) {
+		return '';
+	}
+
+	$slug     = $attributes['slug'];
+	$registry = WP_Block_Patterns_Registry::get_instance();
+	if ( ! $registry->is_registered( $slug ) ) {
+		return '';
+	}
+
+	$pattern = $registry->get_registered( $slug );
+	return do_blocks( $pattern['content'] );
+}
+
+add_action( 'init', 'register_block_core_pattern' );