cpython/Misc/NEWS.d/next/Library/2024-11-23-12-25-06.gh-issue-125866.wEOP66.rst

:func:`urllib.request.pathname2url` now adds an empty authority when
generating a URL for a path that begins with exactly one slash. For example,
the path ``/etc/hosts`` is converted to the scheme-less URL ``///etc/hosts``.
As a result of this change, URLs without authorities are only generated for
relative paths.