From dab0d4043674d9521d3717eb0f74f12c2f74eaff Mon Sep 17 00:00:00 2001
From: Jonathan Desrosiers <desrosj@git.wordpress.org>
Date: Mon, 17 Dec 2018 18:06:42 +0000
Subject: [PATCH] Block Editor: Fix PHP warning when loading editor styles
 while in RTL.

In RTL languages, WordPress adds `style-editor-rtl.css` editor styles to the global `$editor_styles`.
This patch ignores handling these styles if the file is not preset.

Also, clarify the docs for the return value of the `block_version` function.

Props mostafa.s1990, desrosj, mukesh27.

Merges [43923] and [43924] to trunk.

Fixes #45288, #45342.

git-svn-id: https://develop.svn.wordpress.org/trunk@44270 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-admin/edit-form-blocks.php | 12 +++++++-----
 src/wp-includes/blocks.php        |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/wp-admin/edit-form-blocks.php b/src/wp-admin/edit-form-blocks.php
index 8dc7da46f4..bc01ea11e4 100644
--- a/src/wp-admin/edit-form-blocks.php
+++ b/src/wp-admin/edit-form-blocks.php
@@ -197,11 +197,13 @@ if ( $editor_styles && current_theme_supports( 'editor-styles' ) ) {
 				);
 			}
 		} else {
-			$file     = get_theme_file_path( $style );
-			$styles[] = array(
-				'css'     => file_get_contents( get_theme_file_path( $style ) ),
-				'baseURL' => get_theme_file_uri( $style ),
-			);
+			$file = get_theme_file_path( $style );
+			if ( file_exists( $file ) ) {
+				$styles[] = array(
+					'css'     => file_get_contents( $file ),
+					'baseURL' => get_theme_file_uri( $style ),
+				);
+			}
 		}
 	}
 }
diff --git a/src/wp-includes/blocks.php b/src/wp-includes/blocks.php
index e584dc377d..fe1cb685ee 100644
--- a/src/wp-includes/blocks.php
+++ b/src/wp-includes/blocks.php
@@ -283,7 +283,7 @@ function _restore_wpautop_hook( $content ) {
  * @since 5.0.0
  *
  * @param string $content Content to test.
- * @return int The block format version.
+ * @return int The block format version is 1 if the content contains one or more blocks, 0 otherwise.
  */
 function block_version( $content ) {
 	return has_blocks( $content ) ? 1 : 0;