From 792c3035ca900314fad7ab8afae3486ed9951329 Mon Sep 17 00:00:00 2001
From: Anton Vlasenko <43744263+anton-vlasenko@users.noreply.github.com>
Date: Tue, 7 Dec 2021 01:27:31 +0100
Subject: [PATCH] Refactor the `gutenberg_is_fse_theme` function to use
 `wp_is_block_theme` (#37161)

* Rename wp_is_block_template_theme to wp_is_block_theme

* Use wp_is_block_theme (if it's available).
Add a note about future deprecation of the gutenberg_is_fse_theme function.
---
 lib/compat/wordpress-5.9/template-parts.php | 4 ++--
 lib/compat/wordpress-5.9/templates.php      | 4 ++--
 lib/full-site-editing/full-site-editing.php | 8 ++++++++
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/compat/wordpress-5.9/template-parts.php b/lib/compat/wordpress-5.9/template-parts.php
index 1d84d00afbe48a..a095bbe6643e05 100644
--- a/lib/compat/wordpress-5.9/template-parts.php
+++ b/lib/compat/wordpress-5.9/template-parts.php
@@ -12,8 +12,8 @@
  */
 
 // Only run any of the code in this file if the version is less than 5.9.
-// wp_is_block_template_theme was introduced in 5.9.
-if ( ! function_exists( 'wp_is_block_template_theme' ) ) {
+// wp_is_block_theme was introduced in 5.9.
+if ( ! function_exists( 'wp_is_block_theme' ) ) {
 	/**
 	 * Registers block editor 'wp_template_part' post type.
 	 */
diff --git a/lib/compat/wordpress-5.9/templates.php b/lib/compat/wordpress-5.9/templates.php
index 93b8c40a8c0cf2..c6f41eff9c9d66 100644
--- a/lib/compat/wordpress-5.9/templates.php
+++ b/lib/compat/wordpress-5.9/templates.php
@@ -12,8 +12,8 @@
  */
 
 // Only run any of the code in this file if the version is less than 5.9.
-// wp_is_block_template_theme was introduced in 5.9.
-if ( ! function_exists( 'wp_is_block_template_theme' ) ) {
+// wp_is_block_theme was introduced in 5.9.
+if ( ! function_exists( 'wp_is_block_theme' ) ) {
 	/**
 	 * Registers block editor 'wp_template' post type.
 	 */
diff --git a/lib/full-site-editing/full-site-editing.php b/lib/full-site-editing/full-site-editing.php
index 8320d1b32ccb3b..9e04a8388d2671 100644
--- a/lib/full-site-editing/full-site-editing.php
+++ b/lib/full-site-editing/full-site-editing.php
@@ -8,9 +8,17 @@
 /**
  * Returns whether the current theme is an FSE theme or not.
  *
+ * Note: once 5.9 is the minimum supported WordPress version for the Gutenberg
+ * plugin, we must deprecate this function and
+ * use wp_is_block_theme instead.
+ *
  * @return boolean Whether the current theme is an FSE theme or not.
  */
 function gutenberg_is_fse_theme() {
+	if ( function_exists( 'wp_is_block_theme' ) ) {
+		return wp_is_block_theme();
+	}
+
 	return is_readable( get_theme_file_path( '/block-templates/index.html' ) ) ||
 		is_readable( get_theme_file_path( '/templates/index.html' ) );
 }