bug#53941: Last-minute socks.el improvements for Emacs 29?

[J.P.]

Hi people, maintainers,

I've lifted some fixes and minor enhancements from my POC stuff posted
to this thread earlier this year. Nothing is directly Tor related, so I
can create a new bug report, if necessary.

The second patch fixes a problem involving SOCKS 5 error handling. It
also adds support for SOCKS 4a, which allows tools that don't speak
SOCKS 5, like socat, to resolve host names. The third addresses a couple
FIXMEs but no bugs, strictly speaking. The fourth is just a demo [1].
Happy to explain whatever in detail.

Thanks,
J.P.


[1] The fourth patch demos a possible approach for tightening the
    integration between socks and url-proxy, but it's not fit for
    inclusion in Emacs 29. To try it out with Tor, do something like

      (setq url-proxy-services '(("https" . "socks5h://127.0.0.1:9050"))
            socks-username "foo"
            socks-password "")

    followed by an M-x eww RET https://check.torproject.org RET. (Note
    that this still leaks DNS.)

0001-Don-t-hard-code-server-ports-in-SOCKS-tests.patch
Description: Text Data

0002-Improve-SOCKS-error-handling-and-add-support-for-4a.patch
Description: Text Data

0003-Simplify-network-stream-openers-in-socks.el.patch
Description: Text Data

0004-POC-30.0.50-Integrate-the-socks-and-url-libraries.patch
Description: Text Data