Upgrade/Install: Introduce a filter for the result of `WP_Upgrader::install_package()`.

This allows for the capture and usage of error data from the method, to facilitate a potential plugin/theme rollback in the event of an update failure.

Props afragen, dd32.
Fixes #52381.
Built from https://develop.svn.wordpress.org/trunk@50151


git-svn-id: http://core.svn.wordpress.org/trunk@49830 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/class-wp-upgrader.php

@@ -798,6 +798,16 @@ class WP_Upgrader {
 			)
 		);
 
+		/**
+		 * Filters the result of WP_Upgrader::install_package().
+		 *
+		 * @since 5.7.0
+		 *
+		 * @param array|WP_Error $result     Result from WP_Upgrader::install_package().
+		 * @param array          $hook_extra Extra arguments passed to hooked filters.
+		 */
+		$result = apply_filters( 'upgrader_install_package_result', $result, $options['hook_extra'] );
+
 		$this->skin->set_result( $result );
 		if ( is_wp_error( $result ) ) {
 			$this->skin->error( $result );

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-alpha-50150';
+$wp_version = '5.7-alpha-50151';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.