From 55e1f89d05b865f59cc5edf6943d8e1ec92f1ae4 Mon Sep 17 00:00:00 2001
From: Jonny Harris <spacedmonkey@users.noreply.github.com>
Date: Tue, 22 Jun 2021 01:02:58 +0100
Subject: [PATCH] Widget preivew not working if widget registered via a
 instance (#32781)

---
 lib/widgets-api.php                           | 35 ++++++++++++++++---
 .../src/blocks/legacy-widget/index.php        | 11 +++---
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/lib/widgets-api.php b/lib/widgets-api.php
index cf626da1618dd..f89d34fa1d304 100644
--- a/lib/widgets-api.php
+++ b/lib/widgets-api.php
@@ -217,6 +217,32 @@ function gutenberg_get_widget_instance( $id ) {
 	}
 }
 
+if ( ! function_exists( 'gutenberg_get_widget_key' ) ) {
+	/**
+	 * Returns the registered key for the given widget type.
+	 *
+	 * Belongs in WP_Widget_Factory when merged to Core.
+	 *
+	 * Can be removed when minimum WordPress version is 5.8.
+	 *
+	 * @since 10.3.0
+	 *
+	 * @param string $id_base Widget type ID.
+	 * @return string
+	 */
+	function gutenberg_get_widget_key( $id_base ) {
+		global $wp_widget_factory;
+
+		foreach ( $wp_widget_factory->widgets as $key => $widget_object ) {
+			if ( $widget_object->id_base === $id_base ) {
+				return $key;
+			}
+		}
+
+		return '';
+	}
+}
+
 if ( ! function_exists( 'gutenberg_get_widget_object' ) ) {
 	/**
 	 * Returns the registered WP_Widget object for the given widget type.
@@ -233,12 +259,11 @@ function gutenberg_get_widget_instance( $id ) {
 	function gutenberg_get_widget_object( $id_base ) {
 		global $wp_widget_factory;
 
-		foreach ( $wp_widget_factory->widgets as $widget_object ) {
-			if ( $widget_object->id_base === $id_base ) {
-				return $widget_object;
-			}
+		$key = gutenberg_get_widget_key( $id_base );
+		if ( ! $key ) {
+			return null;
 		}
 
-		return null;
+		return $wp_widget_factory->widgets[ $key ];
 	}
 }
diff --git a/packages/widgets/src/blocks/legacy-widget/index.php b/packages/widgets/src/blocks/legacy-widget/index.php
index 69277342a17b9..e832c98c24da5 100644
--- a/packages/widgets/src/blocks/legacy-widget/index.php
+++ b/packages/widgets/src/blocks/legacy-widget/index.php
@@ -24,13 +24,14 @@ function render_block_core_legacy_widget( $attributes ) {
 		return '';
 	}
 
-	if ( method_exists( $wp_widget_factory, 'get_widget_object' ) ) {
-		$widget_object = $wp_widget_factory->get_widget_object( $attributes['idBase'] );
+	$id_base = $attributes['idBase'];
+	if ( method_exists( $wp_widget_factory, 'get_widget_key' ) ) {
+		$widget_key = $wp_widget_factory->get_widget_key( $id_base );
 	} else {
-		$widget_object = gutenberg_get_widget_object( $attributes['idBase'] );
+		$widget_key = gutenberg_get_widget_key( $id_base );
 	}
 
-	if ( ! $widget_object ) {
+	if ( ! $widget_key ) {
 		return '';
 	}
 
@@ -45,7 +46,7 @@ function render_block_core_legacy_widget( $attributes ) {
 	}
 
 	ob_start();
-	the_widget( get_class( $widget_object ), $instance );
+	the_widget( $widget_key, $instance );
 	return ob_get_clean();
 }