1 files changed, 65 insertions, 0 deletions
diff --git a/wp-includes/blocks/block.php b/wp-includes/blocks/block.php
new file mode 100644
index 0000000..d51b35d
--- /dev/null
+++ b/wp-includes/blocks/block.php
@@ -0,0 +1,65 @@
+<?php
+/**
+ * Server-side rendering of the `core/block` block.
+ *
+ * @package WordPress
+ */
+
+/**
+ * Renders the `core/block` block on server.
+ *
+ * @param array $attributes The block attributes.
+ *
+ * @return string Rendered HTML of the referenced block.
+ */
+function render_block_core_block( $attributes ) {
+	static $seen_refs = array();
+
+	if ( empty( $attributes['ref'] ) ) {
+		return '';
+	}
+
+	$reusable_block = get_post( $attributes['ref'] );
+	if ( ! $reusable_block || 'wp_block' !== $reusable_block->post_type ) {
+		return '';
+	}
+
+	if ( isset( $seen_refs[ $attributes['ref'] ] ) ) {
+		// WP_DEBUG_DISPLAY must only be honored when WP_DEBUG. This precedent
+		// is set in `wp_debug_mode()`.
+		$is_debug = WP_DEBUG && WP_DEBUG_DISPLAY;
+
+		return $is_debug ?
+			// translators: Visible only in the front end, this warning takes the place of a faulty block.
+			__( '[block rendering halted]' ) :
+			'';
+	}
+
+	if ( 'publish' !== $reusable_block->post_status || ! empty( $reusable_block->post_password ) ) {
+		return '';
+	}
+
+	$seen_refs[ $attributes['ref'] ] = true;
+
+	// Handle embeds for reusable blocks.
+	global $wp_embed;
+	$content = $wp_embed->run_shortcode( $reusable_block->post_content );
+	$content = $wp_embed->autoembed( $content );
+
+	$content = do_blocks( $content );
+	unset( $seen_refs[ $attributes['ref'] ] );
+	return $content;
+}
+
+/**
+ * Registers the `core/block` block.
+ */
+function register_block_core_block() {
+	register_block_type_from_metadata(
+		__DIR__ . '/block',
+		array(
+			'render_callback' => 'render_block_core_block',
+		)
+	);
+}
+add_action( 'init', 'register_block_core_block' );