--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/blocks/post-comments-form.php	Tue Sep 27 16:37:53 2022 +0200
@@ -0,0 +1,80 @@
+<?php
+/**
+ * Server-side rendering of the `core/post-comments-form` block.
+ *
+ * @package WordPress
+ */
+
+/**
+ * Renders the `core/post-comments-form` block on the server.
+ *
+ * @param array    $attributes Block attributes.
+ * @param string   $content    Block default content.
+ * @param WP_Block $block      Block instance.
+ * @return string Returns the filtered post comments form for the current post.
+ */
+function render_block_core_post_comments_form( $attributes, $content, $block ) {
+	if ( ! isset( $block->context['postId'] ) ) {
+		return '';
+	}
+
+	if ( post_password_required( $block->context['postId'] ) ) {
+		return;
+	}
+
+	$classes = 'comment-respond'; // See comment further below.
+	if ( isset( $attributes['textAlign'] ) ) {
+		$classes .= ' has-text-align-' . $attributes['textAlign'];
+	}
+
+	$wrapper_attributes = get_block_wrapper_attributes( array( 'class' => $classes ) );
+
+	add_filter( 'comment_form_defaults', 'post_comments_form_block_form_defaults' );
+
+	ob_start();
+	comment_form( array(), $block->context['postId'] );
+	$form = ob_get_clean();
+
+	remove_filter( 'comment_form_defaults', 'post_comments_form_block_form_defaults' );
+
+	// We use the outermost wrapping `<div />` returned by `comment_form()`
+	// which is identified by its default classname `comment-respond` to inject
+	// our wrapper attributes. This way, it is guaranteed that all styling applied
+	// to the block is carried along when the comment form is moved to the location
+	// of the 'Reply' link that the user clicked by Core's `comment-reply.js` script.
+	$form = str_replace( 'class="comment-respond"', $wrapper_attributes, $form );
+
+	// Enqueue the comment-reply script.
+	wp_enqueue_script( 'comment-reply' );
+
+	return $form;
+}
+
+/**
+ * Registers the `core/post-comments-form` block on the server.
+ */
+function register_block_core_post_comments_form() {
+	register_block_type_from_metadata(
+		__DIR__ . '/post-comments-form',
+		array(
+			'render_callback' => 'render_block_core_post_comments_form',
+		)
+	);
+}
+add_action( 'init', 'register_block_core_post_comments_form' );
+
+/**
+ * Use the button block classes for the form-submit button.
+ *
+ * @param array $fields The default comment form arguments.
+ *
+ * @return array Returns the modified fields.
+ */
+function post_comments_form_block_form_defaults( $fields ) {
+	if ( wp_is_block_theme() ) {
+		$fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="%3$s wp-block-button__link" value="%4$s" />';
+		$fields['submit_field']  = '<p class="form-submit wp-block-button">%1$s %2$s</p>';
+	}
+
+	return $fields;
+}