From 71f37fe636dcdf5b69f833fdafe636262c002127 Mon Sep 17 00:00:00 2001
From: whyisjake <whyisjake@git.wordpress.org>
Date: Tue, 8 Jun 2021 22:38:58 +0000
Subject: [PATCH] Editor: Ensure that the block editor can be used on the page
 post type.

Additionally, add a notice for when you are editing the "latest posts" page.

Fixes #45537.

Props cameronjonesweb, swissspidy, hannahmalcolm, Fantasy1125, ArnaudBan, grantmkin, youknowriad, knutsp, SergeyBiryukov, audrasjb, whyisjake.

Built from https://develop.svn.wordpress.org/trunk@51116


git-svn-id: http://core.svn.wordpress.org/trunk@50725 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-admin/edit-form-blocks.php  |  4 ++++
 wp-admin/includes/post.php     |  5 -----
 wp-admin/includes/template.php | 17 +++++++++++++++++
 wp-includes/version.php        |  2 +-
 4 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/wp-admin/edit-form-blocks.php b/wp-admin/edit-form-blocks.php
index 71328d0ad5..408806b125 100644
--- a/wp-admin/edit-form-blocks.php
+++ b/wp-admin/edit-form-blocks.php
@@ -313,6 +313,10 @@ $script = sprintf(
 );
 wp_add_inline_script( 'wp-edit-post', $script );
 
+if ( (int) get_option( 'page_for_posts' ) === (int) $post->ID ) {
+	add_action( 'admin_enqueue_scripts', '_wp_block_editor_posts_page_notice' );
+}
+
 require_once ABSPATH . 'wp-admin/admin-header.php';
 ?>
 
diff --git a/wp-admin/includes/post.php b/wp-admin/includes/post.php
index c208c3dae3..9b66f92d21 100644
--- a/wp-admin/includes/post.php
+++ b/wp-admin/includes/post.php
@@ -2134,11 +2134,6 @@ function use_block_editor_for_post( $post ) {
 		return false;
 	}
 
-	// The posts page can't be edited in the block editor.
-	if ( absint( get_option( 'page_for_posts' ) ) === $post->ID && empty( $post->post_content ) ) {
-		return false;
-	}
-
 	$use_block_editor = use_block_editor_for_post_type( $post->post_type );
 
 	/**
diff --git a/wp-admin/includes/template.php b/wp-admin/includes/template.php
index 8e22630d6a..fedf3fcbc9 100644
--- a/wp-admin/includes/template.php
+++ b/wp-admin/includes/template.php
@@ -2674,3 +2674,20 @@ function wp_star_rating( $args = array() ) {
 function _wp_posts_page_notice() {
 	echo '<div class="notice notice-warning inline"><p>' . __( 'You are currently editing the page that shows your latest posts.' ) . '</p></div>';
 }
+
+/**
+ * Output a notice when editing the page for posts in the block editor (internal use only).
+ *
+ * @ignore
+ * @since 5.8.0
+ */
+function _wp_block_editor_posts_page_notice() {
+	wp_add_inline_script(
+		'wp-notices',
+		sprintf(
+			'wp.data.dispatch( "core/notices" ).createWarningNotice( "%s", { isDismissible: false } )',
+			__( 'You are currently editing the page that shows your latest posts.' )
+		),
+		'after'
+	);
+}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 6c0e8509e5..35de626733 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-alpha-51115';
+$wp_version = '5.8-alpha-51116';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.