Plugins: When loading a plugin in a "sandbox" on activation, do it in a separate function.

This avoids accidentally overriding some variables in the scope of `activate_plugin()`, e.g. `$silent` or `$network_wide`.

Plugins expecting to have access to `$network_wide` directly on inclusion should receive it as an argument of the activation hook callback instead, on any of these actions:

* `activate_plugin`
* `activate_{$plugin}`
* `activated_plugin`

Follow-up to [28644].

Props Mike_Cowobo, dd32, DrewAPicture, mensmaximus, SergeyBiryukov.
Fixes #31104.
Built from https://develop.svn.wordpress.org/trunk@50787


git-svn-id: http://core.svn.wordpress.org/trunk@50396 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/plugin.php

@@ -661,14 +661,8 @@ function activate_plugin( $plugin, $redirect = '', $network_wide = false, $silen
 
 		ob_start();
 
-		if ( ! defined( 'WP_SANDBOX_SCRAPING' ) ) {
-			define( 'WP_SANDBOX_SCRAPING', true );
-		}
-
-		wp_register_plugin_realpath( WP_PLUGIN_DIR . '/' . $plugin );
-		$_wp_plugin_file = $plugin;
-		include_once WP_PLUGIN_DIR . '/' . $plugin;
-		$plugin = $_wp_plugin_file; // Avoid stomping of the $plugin variable in a plugin.
+		// Load the plugin to test whether it throws any errors.
+		plugin_sandbox_scrape( $plugin );
 
 		if ( ! $silent ) {
 			/**
@@ -732,6 +726,7 @@ function activate_plugin( $plugin, $redirect = '', $network_wide = false, $silen
 			$output = ob_get_clean();
 			return new WP_Error( 'unexpected_output', __( 'The plugin generated unexpected output.' ), $output );
 		}
+
 		ob_end_clean();
 	}
 

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-alpha-50786';
+$wp_version = '5.8-alpha-50787';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.