set_thumbnail

gistfile1.txt

$tmp = download_url( $url );
		
		$img = basename( $url );
		$info = pathinfo( $img );
		$ext = isset( $info['extension'] ) ? '.' . $info['extension'] : '.jpg';

		preg_match( '/[^\?]+\.(jpg|JPG|jpe|JPE|jpeg|JPEG|gif|GIF|png|PNG|tmp)/', $tmp, $matches );
		//$file_array['name'] = basename( $matches[0] );
		$file_array['name'] = str_replace( '.tmp', $ext, basename( $matches[0] ) );
		$file_array['tmp_name'] = $tmp;