Bug report

Bug description:

The tests of lxml do (simplified):

fromurllib.parseimporturljoinurljoin('file:','/foo/bar')

• On Python 3.13.0 and earlier, the result of the urljoin call isfile:///foo/bar.
• On Python 3.14.0a1, the result of the urljoin call isfile:/foo/bar.

This change of behavior was introduced infc897fc#123273 cc@serhiy-storchaka

The NEWS entry in that change does not seem to indicate this change was intentional.

CPython versions tested on:

3.14, CPython main branch

Operating systems tested on:

Linux