Update implementation

Author: aristath

db.copy

@@ -13,17 +13,15 @@
 
 define( 'SQLITE_DB_DROPIN_VERSION', '1.8.0' );
 
+// Tweak to allow copy-pasting the file without having to run string-replacements.
+$sqlite_plugin_implementation_folder_path = '{SQLITE_IMPLEMENTATION_FOLDER_PATH}';
+if ( ! file_exists( $sqlite_plugin_implementation_folder_path ) ) { // Check that the folder exists.
+	$sqlite_plugin_implementation_folder_path = realpath( __DIR__ . '/plugins/sqlite-database-integration' );
+}
+
 // Bail early if the SQLite implementation was not located in the plugin.
-$sqlite_db_plugin_folder    = '{SQLITE_IMPLEMENTATION_FOLDER_PATH}';
-$sqlite_db_plugin_db_file   = $sqlite_db_plugin_folder . '/wp-includes/sqlite/db.php';
-$sqlite_db_plugin_main_file = WP_PLUGIN_DIR . '/{SQLITE_PLUGIN}';
-if ( ! file_exists( $sqlite_db_plugin_db_file ) ) {
-	$sqlite_db_plugin_folder    = WP_PLUGIN_DIR . '/sqlite-database-integration';
-	$sqlite_db_plugin_db_file   = $sqlite_db_plugin_folder . '/wp-includes/sqlite/db.php';
-	$sqlite_db_plugin_main_file = $sqlite_db_plugin_folder . '/load.php';
-	if ( ! file_exists( $sqlite_db_plugin_db_file ) ) {
-		return;
-	}
+if ( ! $sqlite_plugin_implementation_folder_path || ! file_exists( $sqlite_plugin_implementation_folder_path . '/wp-includes/sqlite/db.php' ) ) {
+	return;
 }
 
 // Constant for backward compatibility.
@@ -36,23 +34,24 @@ if ( ! defined( 'DB_ENGINE' ) ) {
 }
 
 // Require the implementation from the plugin.
-require_once $sqlite_db_plugin_db_file;
+require_once $sqlite_plugin_implementation_folder_path . '/wp-includes/sqlite/db.php';
 
 // Activate the performance-lab plugin if it is not already activated.
 add_action(
 	'admin_footer',
-	function() use ( $sqlite_db_plugin_main_file ) {
+	function() {
 		if ( defined( 'SQLITE_MAIN_FILE' ) ) {
 			return;
 		}
 		if ( ! function_exists( 'activate_plugin' ) ) {
 			require_once ABSPATH . 'wp-admin/includes/plugin.php';
 		}
-
-		if ( file_exists( $sqlite_db_plugin_main_file ) ) {
-			$plugin_file = str_replace( WP_PLUGIN_DIR . '/', '', $sqlite_db_plugin_main_file );
-			if ( is_plugin_inactive( $plugin_file ) ) {
-				activate_plugin( $plugin_file );
+		if ( is_plugin_inactive( '{SQLITE_PLUGIN}' ) ) {
+			// If `activate_plugin()` returns a value other than null (like WP_Error),
+			// the plugin could not be found. Try with a hardcoded string,
+			// because that probably means the file was directly copy-pasted.
+			if ( null !== activate_plugin( '{SQLITE_PLUGIN}', '', false, true ) ) {
+				activate_plugin( 'sqlite-database-integration/load.php', '', false, true );
 			}
 		}
 	}