From bababb94e2dc4e113ca952a8c3e4fe697c25fef5 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Wed, 24 Jan 2024 17:10:09 +0100
Subject: [PATCH 1/4] Update Navigation block to render hooked inner blocks

---
 .../wordpress-6.5/navigation-block-hooks.php  | 112 ++++++++++++++++++
 lib/load.php                                  |   1 +
 .../block-library/src/navigation/index.php    |  25 +++-
 3 files changed, 135 insertions(+), 3 deletions(-)
 create mode 100644 lib/compat/wordpress-6.5/navigation-block-hooks.php

diff --git a/lib/compat/wordpress-6.5/navigation-block-hooks.php b/lib/compat/wordpress-6.5/navigation-block-hooks.php
new file mode 100644
index 00000000000000..d7a0e888622d25
--- /dev/null
+++ b/lib/compat/wordpress-6.5/navigation-block-hooks.php
@@ -0,0 +1,112 @@
+<?php
+// Injection of hooked blocks into the Navigation block relies on some functions present in WP >= 6.4
+// that have not yet been included in Gutenberg's compatibility layer (lib/compat/wordpress-6.4/block-hooks.php).
+if ( function_exists( 'get_hooked_blocks' ) ) {
+	add_filter( 'rest_prepare_wp_navigation', 'gutenberg_hook_blocks_into_core_navigation_rest_response', 10, 3 );
+	add_action( 'rest_insert_wp_navigation', 'gutenberg_update_ignore_hooked_blocks_meta_core_navigation', 10, 3 );
+}
+
+/**
+ * Updates the post meta with the list of ignored hooked blocks when the navigation is created or updated via the REST API.
+ *
+ * @param WP_Post $post Post object.
+ */
+function gutenberg_update_ignore_hooked_blocks_meta_core_navigation( $post ) {
+	if ( ! isset( $post->ID ) ) {
+		return;
+	}
+
+	// We run the Block Hooks mechanism so it will return the list of ignored hooked blocks
+	// in the mock root Navigation block's metadata attribute.
+	// We ignore the rest of the returned `$markup`; `$post->post_content` already has the hooked
+	// blocks inserted, whereas `$markup` will have them inserted twice.
+	$blocks                = parse_blocks( $post->post_content );
+	$markup                = gutenberg_insert_hooked_blocks_into_navigation_block( $blocks, $post );
+	$root_nav_block        = parse_blocks( $markup )[0];
+	$ignored_hooked_blocks = isset( $root_nav_block['attrs']['metadata']['ignoredHookedBlocks'] )
+		? $root_nav_block['attrs']['metadata']['ignoredHookedBlocks']
+		: array();
+
+	if ( ! empty( $ignored_hooked_blocks ) ) {
+		$existing_ignored_hooked_blocks = get_post_meta( $post->ID, '_wp_ignored_hooked_blocks', true );
+		if ( ! empty( $existing_ignored_hooked_blocks ) ) {
+			$existing_ignored_hooked_blocks = json_decode( $existing_ignored_hooked_blocks, true );
+			$ignored_hooked_blocks          = array_unique( array_merge( $ignored_hooked_blocks, $existing_ignored_hooked_blocks ) );
+		}
+		update_post_meta( $post->ID, '_wp_ignored_hooked_blocks', json_encode( $ignored_hooked_blocks ) );
+	}
+}
+
+/**
+ * Hooks into the REST API response for the core/navigation block and adds the first and last inner blocks.
+ *
+ * @param WP_REST_Response $response The response object.
+ * @param WP_Post          $post     Post object.
+ * @param WP_REST_Request  $request  Request object.
+ * @return WP_REST_Response The response object.
+ */
+function gutenberg_hook_blocks_into_core_navigation_rest_response( $response, $post ) {
+	if ( ! isset( $response->data['content']['raw'] ) || ! isset( $response->data['content']['rendered'] ) ) {
+		return $response;
+	}
+	$parsed_blocks = parse_blocks( $response->data['content']['raw'] );
+	$content       = gutenberg_insert_hooked_blocks_into_navigation_block( $parsed_blocks, $post );
+
+	// Remove mock Navigation block wrapper.
+	$start   = strpos( $content, '-->' ) + strlen( '-->' );
+	$end     = strrpos( $content, '<!--' );
+	$content = substr( $content, $start, $end - $start );
+
+	$response->data['content']['raw']      = $content;
+	$response->data['content']['rendered'] = apply_filters( 'the_content', $content );
+
+	return $response;
+}
+
+/**
+ * Insert hooked blocks into a Navigation block.
+ *
+ * Given a Navigation block's inner blocks and its corresponding `wp_navigation` post object,
+ * this function inserts hooked blocks into it, and returns the serialized inner blocks in a
+ * mock Navigation block wrapper.
+ *
+ * If there are any hooked blocks that need to be inserted as the Navigation block's first or last
+ * children, the `wp_navigation` post's `_wp_ignored_hooked_blocks` meta is checked to see if any
+ * of those hooked blocks should be exempted from insertion.
+ *
+ * @param array   $inner_blocks Parsed inner blocks of a Navigation block.
+ * @param WP_Post $post         `wp_navigation` post object corresponding to the block.
+ * @return string Serialized inner blocks in mock Navigation block wrapper, with hooked blocks inserted, if any.
+ */
+function gutenberg_insert_hooked_blocks_into_navigation_block( $inner_blocks, $post = null ) {
+	$before_block_visitor = null;
+	$after_block_visitor  = null;
+	$hooked_blocks        = get_hooked_blocks();
+	$attributes           = array();
+
+	if ( isset( $post->ID ) ) {
+		$ignored_hooked_blocks = get_post_meta( $post->ID, '_wp_ignored_hooked_blocks', true );
+		if ( ! empty( $ignored_hooked_blocks ) ) {
+			$ignored_hooked_blocks  = json_decode( $ignored_hooked_blocks, true );
+			$attributes['metadata'] = array(
+				'ignoredHookedBlocks' => $ignored_hooked_blocks,
+			);
+		}
+	}
+
+	$mock_anchor_parent_block = array(
+		'blockName'    => 'core/navigation',
+		'attrs'        => $attributes,
+		'innerBlocks'  => $inner_blocks,
+		'innerContent' => array_fill( 0, count( $inner_blocks ), null ),
+	);
+	$before_block_visitor     = null;
+	$after_block_visitor      = null;
+
+	if ( ! empty( $hooked_blocks ) || has_filter( 'hooked_block_types' ) ) {
+		$before_block_visitor = make_before_block_visitor( $hooked_blocks, $post );
+		$after_block_visitor  = make_after_block_visitor( $hooked_blocks, $post );
+	}
+
+	return traverse_and_serialize_block( $mock_anchor_parent_block, $before_block_visitor, $after_block_visitor );
+}
diff --git a/lib/load.php b/lib/load.php
index ea443544d5be4c..ee5a9e097f056c 100644
--- a/lib/load.php
+++ b/lib/load.php
@@ -106,6 +106,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 // WordPress 6.5 compat.
 require __DIR__ . '/compat/wordpress-6.5/blocks.php';
 require __DIR__ . '/compat/wordpress-6.5/block-patterns.php';
+require __DIR__ . '/compat/wordpress-6.5/navigation-block-hooks.php';
 require __DIR__ . '/compat/wordpress-6.5/kses.php';
 require __DIR__ . '/compat/wordpress-6.5/class-wp-script-modules.php';
 require __DIR__ . '/compat/wordpress-6.5/scripts-modules.php';
diff --git a/packages/block-library/src/navigation/index.php b/packages/block-library/src/navigation/index.php
index 8b39a89022f8b2..6df3cbf98dc752 100644
--- a/packages/block-library/src/navigation/index.php
+++ b/packages/block-library/src/navigation/index.php
@@ -190,11 +190,19 @@ private static function get_inner_blocks_from_navigation_post( $attributes ) {
 
 			// 'parse_blocks' includes a null block with '\n\n' as the content when
 			// it encounters whitespace. This code strips it.
-			$compacted_blocks = block_core_navigation_filter_out_empty_blocks( $parsed_blocks );
+			$blocks = block_core_navigation_filter_out_empty_blocks( $parsed_blocks );
+
+			if ( function_exists( 'get_hooked_blocks' ) ) {
+				// Run Block Hooks algorithm to inject hooked blocks.
+				$markup         = gutenberg_insert_hooked_blocks_into_navigation_block( $blocks, $navigation_post );
+				$root_nav_block = parse_blocks( $markup )[0];
+
+				$blocks = isset( $root_nav_block['innerBlocks'] ) ? $root_nav_block['innerBlocks'] : $blocks;
+			}
 
 			// TODO - this uses the full navigation block attributes for the
 			// context which could be refined.
-			return new WP_Block_List( $compacted_blocks, $attributes );
+			return new WP_Block_List( $blocks, $attributes );
 		}
 	}
 
@@ -983,6 +991,17 @@ function block_core_navigation_get_fallback_blocks() {
 		// Normalizing blocks may result in an empty array of blocks if they were all `null` blocks.
 		// In this case default to the (Page List) fallback.
 		$fallback_blocks = ! empty( $maybe_fallback ) ? $maybe_fallback : $fallback_blocks;
+
+		if ( function_exists( 'get_hooked_blocks' ) ) {
+			// Run Block Hooks algorithm to inject hooked blocks.
+			// We have to run it here because we need the post ID of the Navigation block to track ignored hooked blocks.
+			$markup = gutenberg_insert_hooked_blocks_into_navigation_block( $fallback_blocks, $navigation_post );
+			$blocks = parse_blocks( $markup );
+
+			if ( isset( $blocks[0]['innerBlocks'] ) ) {
+				$fallback_blocks = $blocks[0]['innerBlocks'];
+			}
+		}
 	}
 
 	/**
@@ -994,7 +1013,7 @@ function block_core_navigation_get_fallback_blocks() {
 	 *
 	 * @since 5.9.0
 	 *
-	 * @param array[] default fallback blocks provided by the default block mechanic.
+	 * @param array[] $fallback_blocks default fallback blocks provided by the default block mechanic.
 	 */
 	return apply_filters( 'block_core_navigation_render_fallback', $fallback_blocks );
 }

From 2211001ef22f8369d9422426e91b27442bf73625 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Wed, 24 Jan 2024 17:46:51 +0100
Subject: [PATCH 2/4] Rename
 gutenberg_insert_hooked_blocks_into_navigation_block

---
 lib/compat/wordpress-6.5/navigation-block-hooks.php | 6 +++---
 packages/block-library/src/navigation/index.php     | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/compat/wordpress-6.5/navigation-block-hooks.php b/lib/compat/wordpress-6.5/navigation-block-hooks.php
index d7a0e888622d25..9e1879a6dd080d 100644
--- a/lib/compat/wordpress-6.5/navigation-block-hooks.php
+++ b/lib/compat/wordpress-6.5/navigation-block-hooks.php
@@ -21,7 +21,7 @@ function gutenberg_update_ignore_hooked_blocks_meta_core_navigation( $post ) {
 	// We ignore the rest of the returned `$markup`; `$post->post_content` already has the hooked
 	// blocks inserted, whereas `$markup` will have them inserted twice.
 	$blocks                = parse_blocks( $post->post_content );
-	$markup                = gutenberg_insert_hooked_blocks_into_navigation_block( $blocks, $post );
+	$markup                = block_core_navigation_insert_hooked_blocks( $blocks, $post );
 	$root_nav_block        = parse_blocks( $markup )[0];
 	$ignored_hooked_blocks = isset( $root_nav_block['attrs']['metadata']['ignoredHookedBlocks'] )
 		? $root_nav_block['attrs']['metadata']['ignoredHookedBlocks']
@@ -50,7 +50,7 @@ function gutenberg_hook_blocks_into_core_navigation_rest_response( $response, $p
 		return $response;
 	}
 	$parsed_blocks = parse_blocks( $response->data['content']['raw'] );
-	$content       = gutenberg_insert_hooked_blocks_into_navigation_block( $parsed_blocks, $post );
+	$content       = block_core_navigation_insert_hooked_blocks( $parsed_blocks, $post );
 
 	// Remove mock Navigation block wrapper.
 	$start   = strpos( $content, '-->' ) + strlen( '-->' );
@@ -78,7 +78,7 @@ function gutenberg_hook_blocks_into_core_navigation_rest_response( $response, $p
  * @param WP_Post $post         `wp_navigation` post object corresponding to the block.
  * @return string Serialized inner blocks in mock Navigation block wrapper, with hooked blocks inserted, if any.
  */
-function gutenberg_insert_hooked_blocks_into_navigation_block( $inner_blocks, $post = null ) {
+function block_core_navigation_insert_hooked_blocks( $inner_blocks, $post = null ) {
 	$before_block_visitor = null;
 	$after_block_visitor  = null;
 	$hooked_blocks        = get_hooked_blocks();
diff --git a/packages/block-library/src/navigation/index.php b/packages/block-library/src/navigation/index.php
index 6df3cbf98dc752..96fc55623904e4 100644
--- a/packages/block-library/src/navigation/index.php
+++ b/packages/block-library/src/navigation/index.php
@@ -194,7 +194,7 @@ private static function get_inner_blocks_from_navigation_post( $attributes ) {
 
 			if ( function_exists( 'get_hooked_blocks' ) ) {
 				// Run Block Hooks algorithm to inject hooked blocks.
-				$markup         = gutenberg_insert_hooked_blocks_into_navigation_block( $blocks, $navigation_post );
+				$markup         = block_core_navigation_insert_hooked_blocks( $blocks, $navigation_post );
 				$root_nav_block = parse_blocks( $markup )[0];
 
 				$blocks = isset( $root_nav_block['innerBlocks'] ) ? $root_nav_block['innerBlocks'] : $blocks;
@@ -995,7 +995,7 @@ function block_core_navigation_get_fallback_blocks() {
 		if ( function_exists( 'get_hooked_blocks' ) ) {
 			// Run Block Hooks algorithm to inject hooked blocks.
 			// We have to run it here because we need the post ID of the Navigation block to track ignored hooked blocks.
-			$markup = gutenberg_insert_hooked_blocks_into_navigation_block( $fallback_blocks, $navigation_post );
+			$markup = block_core_navigation_insert_hooked_blocks( $fallback_blocks, $navigation_post );
 			$blocks = parse_blocks( $markup );
 
 			if ( isset( $blocks[0]['innerBlocks'] ) ) {

From e4818315307e95103ad2bb93003365a74108d2b4 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Wed, 24 Jan 2024 17:50:11 +0100
Subject: [PATCH 3/4] Rename other functions

---
 lib/compat/wordpress-6.5/navigation-block-hooks.php | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/compat/wordpress-6.5/navigation-block-hooks.php b/lib/compat/wordpress-6.5/navigation-block-hooks.php
index 9e1879a6dd080d..e691144a392a3e 100644
--- a/lib/compat/wordpress-6.5/navigation-block-hooks.php
+++ b/lib/compat/wordpress-6.5/navigation-block-hooks.php
@@ -2,8 +2,8 @@
 // Injection of hooked blocks into the Navigation block relies on some functions present in WP >= 6.4
 // that have not yet been included in Gutenberg's compatibility layer (lib/compat/wordpress-6.4/block-hooks.php).
 if ( function_exists( 'get_hooked_blocks' ) ) {
-	add_filter( 'rest_prepare_wp_navigation', 'gutenberg_hook_blocks_into_core_navigation_rest_response', 10, 3 );
-	add_action( 'rest_insert_wp_navigation', 'gutenberg_update_ignore_hooked_blocks_meta_core_navigation', 10, 3 );
+	add_filter( 'rest_prepare_wp_navigation', 'block_core_navigation_insert_hooked_blocks_into_rest_response', 10, 3 );
+	add_action( 'rest_insert_wp_navigation', 'block_core_navigation_update_ignore_hooked_blocks_meta', 10, 3 );
 }
 
 /**
@@ -11,7 +11,7 @@
  *
  * @param WP_Post $post Post object.
  */
-function gutenberg_update_ignore_hooked_blocks_meta_core_navigation( $post ) {
+function block_core_navigation_update_ignore_hooked_blocks_meta( $post ) {
 	if ( ! isset( $post->ID ) ) {
 		return;
 	}
@@ -45,7 +45,7 @@ function gutenberg_update_ignore_hooked_blocks_meta_core_navigation( $post ) {
  * @param WP_REST_Request  $request  Request object.
  * @return WP_REST_Response The response object.
  */
-function gutenberg_hook_blocks_into_core_navigation_rest_response( $response, $post ) {
+function block_core_navigation_insert_hooked_blocks_into_rest_response( $response, $post ) {
 	if ( ! isset( $response->data['content']['raw'] ) || ! isset( $response->data['content']['rendered'] ) ) {
 		return $response;
 	}

From 2933ca24b84f7b4b3c43131b2447b0389bed0cc0 Mon Sep 17 00:00:00 2001
From: Bernie Reiter <ockham@raz.or.at>
Date: Wed, 24 Jan 2024 17:54:40 +0100
Subject: [PATCH 4/4] Move all code into Nav block

---
 .../wordpress-6.5/navigation-block-hooks.php  | 112 -----------------
 lib/load.php                                  |   1 -
 .../block-library/src/navigation/index.php    | 117 ++++++++++++++++++
 3 files changed, 117 insertions(+), 113 deletions(-)
 delete mode 100644 lib/compat/wordpress-6.5/navigation-block-hooks.php

diff --git a/lib/compat/wordpress-6.5/navigation-block-hooks.php b/lib/compat/wordpress-6.5/navigation-block-hooks.php
deleted file mode 100644
index e691144a392a3e..00000000000000
--- a/lib/compat/wordpress-6.5/navigation-block-hooks.php
+++ /dev/null
@@ -1,112 +0,0 @@
-<?php
-// Injection of hooked blocks into the Navigation block relies on some functions present in WP >= 6.4
-// that have not yet been included in Gutenberg's compatibility layer (lib/compat/wordpress-6.4/block-hooks.php).
-if ( function_exists( 'get_hooked_blocks' ) ) {
-	add_filter( 'rest_prepare_wp_navigation', 'block_core_navigation_insert_hooked_blocks_into_rest_response', 10, 3 );
-	add_action( 'rest_insert_wp_navigation', 'block_core_navigation_update_ignore_hooked_blocks_meta', 10, 3 );
-}
-
-/**
- * Updates the post meta with the list of ignored hooked blocks when the navigation is created or updated via the REST API.
- *
- * @param WP_Post $post Post object.
- */
-function block_core_navigation_update_ignore_hooked_blocks_meta( $post ) {
-	if ( ! isset( $post->ID ) ) {
-		return;
-	}
-
-	// We run the Block Hooks mechanism so it will return the list of ignored hooked blocks
-	// in the mock root Navigation block's metadata attribute.
-	// We ignore the rest of the returned `$markup`; `$post->post_content` already has the hooked
-	// blocks inserted, whereas `$markup` will have them inserted twice.
-	$blocks                = parse_blocks( $post->post_content );
-	$markup                = block_core_navigation_insert_hooked_blocks( $blocks, $post );
-	$root_nav_block        = parse_blocks( $markup )[0];
-	$ignored_hooked_blocks = isset( $root_nav_block['attrs']['metadata']['ignoredHookedBlocks'] )
-		? $root_nav_block['attrs']['metadata']['ignoredHookedBlocks']
-		: array();
-
-	if ( ! empty( $ignored_hooked_blocks ) ) {
-		$existing_ignored_hooked_blocks = get_post_meta( $post->ID, '_wp_ignored_hooked_blocks', true );
-		if ( ! empty( $existing_ignored_hooked_blocks ) ) {
-			$existing_ignored_hooked_blocks = json_decode( $existing_ignored_hooked_blocks, true );
-			$ignored_hooked_blocks          = array_unique( array_merge( $ignored_hooked_blocks, $existing_ignored_hooked_blocks ) );
-		}
-		update_post_meta( $post->ID, '_wp_ignored_hooked_blocks', json_encode( $ignored_hooked_blocks ) );
-	}
-}
-
-/**
- * Hooks into the REST API response for the core/navigation block and adds the first and last inner blocks.
- *
- * @param WP_REST_Response $response The response object.
- * @param WP_Post          $post     Post object.
- * @param WP_REST_Request  $request  Request object.
- * @return WP_REST_Response The response object.
- */
-function block_core_navigation_insert_hooked_blocks_into_rest_response( $response, $post ) {
-	if ( ! isset( $response->data['content']['raw'] ) || ! isset( $response->data['content']['rendered'] ) ) {
-		return $response;
-	}
-	$parsed_blocks = parse_blocks( $response->data['content']['raw'] );
-	$content       = block_core_navigation_insert_hooked_blocks( $parsed_blocks, $post );
-
-	// Remove mock Navigation block wrapper.
-	$start   = strpos( $content, '-->' ) + strlen( '-->' );
-	$end     = strrpos( $content, '<!--' );
-	$content = substr( $content, $start, $end - $start );
-
-	$response->data['content']['raw']      = $content;
-	$response->data['content']['rendered'] = apply_filters( 'the_content', $content );
-
-	return $response;
-}
-
-/**
- * Insert hooked blocks into a Navigation block.
- *
- * Given a Navigation block's inner blocks and its corresponding `wp_navigation` post object,
- * this function inserts hooked blocks into it, and returns the serialized inner blocks in a
- * mock Navigation block wrapper.
- *
- * If there are any hooked blocks that need to be inserted as the Navigation block's first or last
- * children, the `wp_navigation` post's `_wp_ignored_hooked_blocks` meta is checked to see if any
- * of those hooked blocks should be exempted from insertion.
- *
- * @param array   $inner_blocks Parsed inner blocks of a Navigation block.
- * @param WP_Post $post         `wp_navigation` post object corresponding to the block.
- * @return string Serialized inner blocks in mock Navigation block wrapper, with hooked blocks inserted, if any.
- */
-function block_core_navigation_insert_hooked_blocks( $inner_blocks, $post = null ) {
-	$before_block_visitor = null;
-	$after_block_visitor  = null;
-	$hooked_blocks        = get_hooked_blocks();
-	$attributes           = array();
-
-	if ( isset( $post->ID ) ) {
-		$ignored_hooked_blocks = get_post_meta( $post->ID, '_wp_ignored_hooked_blocks', true );
-		if ( ! empty( $ignored_hooked_blocks ) ) {
-			$ignored_hooked_blocks  = json_decode( $ignored_hooked_blocks, true );
-			$attributes['metadata'] = array(
-				'ignoredHookedBlocks' => $ignored_hooked_blocks,
-			);
-		}
-	}
-
-	$mock_anchor_parent_block = array(
-		'blockName'    => 'core/navigation',
-		'attrs'        => $attributes,
-		'innerBlocks'  => $inner_blocks,
-		'innerContent' => array_fill( 0, count( $inner_blocks ), null ),
-	);
-	$before_block_visitor     = null;
-	$after_block_visitor      = null;
-
-	if ( ! empty( $hooked_blocks ) || has_filter( 'hooked_block_types' ) ) {
-		$before_block_visitor = make_before_block_visitor( $hooked_blocks, $post );
-		$after_block_visitor  = make_after_block_visitor( $hooked_blocks, $post );
-	}
-
-	return traverse_and_serialize_block( $mock_anchor_parent_block, $before_block_visitor, $after_block_visitor );
-}
diff --git a/lib/load.php b/lib/load.php
index ee5a9e097f056c..ea443544d5be4c 100644
--- a/lib/load.php
+++ b/lib/load.php
@@ -106,7 +106,6 @@ function gutenberg_is_experiment_enabled( $name ) {
 // WordPress 6.5 compat.
 require __DIR__ . '/compat/wordpress-6.5/blocks.php';
 require __DIR__ . '/compat/wordpress-6.5/block-patterns.php';
-require __DIR__ . '/compat/wordpress-6.5/navigation-block-hooks.php';
 require __DIR__ . '/compat/wordpress-6.5/kses.php';
 require __DIR__ . '/compat/wordpress-6.5/class-wp-script-modules.php';
 require __DIR__ . '/compat/wordpress-6.5/scripts-modules.php';
diff --git a/packages/block-library/src/navigation/index.php b/packages/block-library/src/navigation/index.php
index 96fc55623904e4..0f67a63e7acf27 100644
--- a/packages/block-library/src/navigation/index.php
+++ b/packages/block-library/src/navigation/index.php
@@ -1342,3 +1342,120 @@ function block_core_navigation_get_most_recently_published_navigation() {
 
 	return null;
 }
+
+/**
+ * Insert hooked blocks into a Navigation block.
+ *
+ * Given a Navigation block's inner blocks and its corresponding `wp_navigation` post object,
+ * this function inserts hooked blocks into it, and returns the serialized inner blocks in a
+ * mock Navigation block wrapper.
+ *
+ * If there are any hooked blocks that need to be inserted as the Navigation block's first or last
+ * children, the `wp_navigation` post's `_wp_ignored_hooked_blocks` meta is checked to see if any
+ * of those hooked blocks should be exempted from insertion.
+ *
+ * @param array   $inner_blocks Parsed inner blocks of a Navigation block.
+ * @param WP_Post $post         `wp_navigation` post object corresponding to the block.
+ * @return string Serialized inner blocks in mock Navigation block wrapper, with hooked blocks inserted, if any.
+ */
+function block_core_navigation_insert_hooked_blocks( $inner_blocks, $post = null ) {
+	$before_block_visitor = null;
+	$after_block_visitor  = null;
+	$hooked_blocks        = get_hooked_blocks();
+	$attributes           = array();
+
+	if ( isset( $post->ID ) ) {
+		$ignored_hooked_blocks = get_post_meta( $post->ID, '_wp_ignored_hooked_blocks', true );
+		if ( ! empty( $ignored_hooked_blocks ) ) {
+			$ignored_hooked_blocks  = json_decode( $ignored_hooked_blocks, true );
+			$attributes['metadata'] = array(
+				'ignoredHookedBlocks' => $ignored_hooked_blocks,
+			);
+		}
+	}
+
+	$mock_anchor_parent_block = array(
+		'blockName'    => 'core/navigation',
+		'attrs'        => $attributes,
+		'innerBlocks'  => $inner_blocks,
+		'innerContent' => array_fill( 0, count( $inner_blocks ), null ),
+	);
+	$before_block_visitor     = null;
+	$after_block_visitor      = null;
+
+	if ( ! empty( $hooked_blocks ) || has_filter( 'hooked_block_types' ) ) {
+		$before_block_visitor = make_before_block_visitor( $hooked_blocks, $post );
+		$after_block_visitor  = make_after_block_visitor( $hooked_blocks, $post );
+	}
+
+	return traverse_and_serialize_block( $mock_anchor_parent_block, $before_block_visitor, $after_block_visitor );
+}
+
+/**
+ * Updates the post meta with the list of ignored hooked blocks when the navigation is created or updated via the REST API.
+ *
+ * @param WP_Post $post Post object.
+ */
+function block_core_navigation_update_ignore_hooked_blocks_meta( $post ) {
+	if ( ! isset( $post->ID ) ) {
+		return;
+	}
+
+	// We run the Block Hooks mechanism so it will return the list of ignored hooked blocks
+	// in the mock root Navigation block's metadata attribute.
+	// We ignore the rest of the returned `$markup`; `$post->post_content` already has the hooked
+	// blocks inserted, whereas `$markup` will have them inserted twice.
+	$blocks                = parse_blocks( $post->post_content );
+	$markup                = block_core_navigation_insert_hooked_blocks( $blocks, $post );
+	$root_nav_block        = parse_blocks( $markup )[0];
+	$ignored_hooked_blocks = isset( $root_nav_block['attrs']['metadata']['ignoredHookedBlocks'] )
+		? $root_nav_block['attrs']['metadata']['ignoredHookedBlocks']
+		: array();
+
+	if ( ! empty( $ignored_hooked_blocks ) ) {
+		$existing_ignored_hooked_blocks = get_post_meta( $post->ID, '_wp_ignored_hooked_blocks', true );
+		if ( ! empty( $existing_ignored_hooked_blocks ) ) {
+			$existing_ignored_hooked_blocks = json_decode( $existing_ignored_hooked_blocks, true );
+			$ignored_hooked_blocks          = array_unique( array_merge( $ignored_hooked_blocks, $existing_ignored_hooked_blocks ) );
+		}
+		update_post_meta( $post->ID, '_wp_ignored_hooked_blocks', json_encode( $ignored_hooked_blocks ) );
+	}
+}
+
+// Injection of hooked blocks into the Navigation block relies on some functions present in WP >= 6.4
+// that are not present in Gutenberg's WP 6.4 compatibility layer.
+if ( function_exists( 'get_hooked_blocks' ) ) {
+	add_action( 'rest_insert_wp_navigation', 'block_core_navigation_update_ignore_hooked_blocks_meta', 10, 3 );
+}
+
+/**
+ * Hooks into the REST API response for the core/navigation block and adds the first and last inner blocks.
+ *
+ * @param WP_REST_Response $response The response object.
+ * @param WP_Post          $post     Post object.
+ * @param WP_REST_Request  $request  Request object.
+ * @return WP_REST_Response The response object.
+ */
+function block_core_navigation_insert_hooked_blocks_into_rest_response( $response, $post ) {
+	if ( ! isset( $response->data['content']['raw'] ) || ! isset( $response->data['content']['rendered'] ) ) {
+		return $response;
+	}
+	$parsed_blocks = parse_blocks( $response->data['content']['raw'] );
+	$content       = block_core_navigation_insert_hooked_blocks( $parsed_blocks, $post );
+
+	// Remove mock Navigation block wrapper.
+	$start   = strpos( $content, '-->' ) + strlen( '-->' );
+	$end     = strrpos( $content, '<!--' );
+	$content = substr( $content, $start, $end - $start );
+
+	$response->data['content']['raw']      = $content;
+	$response->data['content']['rendered'] = apply_filters( 'the_content', $content );
+
+	return $response;
+}
+
+// Injection of hooked blocks into the Navigation block relies on some functions present in WP >= 6.4
+// that are not present in Gutenberg's WP 6.4 compatibility layer.
+if ( function_exists( 'get_hooked_blocks' ) ) {
+	add_filter( 'rest_prepare_wp_navigation', 'block_core_navigation_insert_hooked_blocks_into_rest_response', 10, 3 );
+}