Thank you for your reports OndrejPtak and frathgeber.

Indeed, the behavior change was unintended. PR 25057 tries to to restore the old behavior. Query and fragment are now preserved in the server URL.

But there are still minor differences. Empty query and fragment are stripped from the URL, so "http://example.org/RPC2?", "http://example.org/RPC2#" and "http://example.org/RPC2" refer to the same connection point. I am not sure that it is important. It would be not easy to preserve the old behavior in these corner cases.