Yes the file belongs to Textpattern.
So this script have an issue with 5.3. (even the author thinks not
It doesn't really solve the issue of errors being displayed with "display_errors = Off",
I only can say the same as above:
XAMPP doesn't show E_DEPRECATED errror.
--> So if you have not changed the default "php.ini", this script is setting error_reporting and display_errors itself to some value.