protected function setCurrentZip( $fullpath ) {

		$result = $this->zip->open( $fullpath );
		if ( true !== $result ) {
			throw new \Exception( 'Opening epub file failed' );
		}

		/* Safety dance */

		$ok = $this->getZipContent( 'META-INF/container.xml' );
		if ( ! $ok ) {
			throw new \Exception( 'Bad or corrupted META-INF/container.xml' );
		}

	}