pytest failures with OpenSSL 4

Hi there,

I applied the OpenSSL4 support patches proposed by Joe 
(https://github.com/apache/httpd/pull/642).

Builds run fine using them against OpenSSL 3.5.6 and also 4.0.0, no 
warnings or even errors. Platforms tested were RHEL 8 and 10.

Perl test framework runs fine with a variety of OpenSSL versions in the 
test client (did not use OpenSSL 4 in thhe client, but 3.6, 3.5 and 3.0.

pytest runs fine with these patches when using httpd build with OpenSSL 
3.5.6.

pytest shows mostly reproducible failures when using httpd build with 
OpenSSL 4.

All failing test use the h2proxy, so I guess the failures are related to 
mod_proxy_http2. Of course, the tests are only run when using a threaded 
MPM, so not for prefork.

These tests fail always for me:

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_05_echo_fail_many

modules/http2/test_711_load_post_cgi.py::TestLoadCgi::test_h2_711_12[0]

modules/http2/test_712_buffering.py::TestBuffering::test_h2_712_02 - B...

modules/http2/test_712_buffering.py::TestBuffering::test_h2_712_03 - B...

These tests fail mostly:

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_01_echo_uploads[data-100k]

or
modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_01_echo_uploads[data-1m]

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_02_echo_delayed[data-100k]

or

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_02_echo_delayed[data-1m]

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_03_echo_fail_early[data-100k]

or

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_03_echo_fail_early[data-1m]

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_04_echo_fail_late[data-100k]

or

modules/http2/test_601_h2proxy_twisted.py::TestH2ProxyTwisted::test_h2_601_04_echo_fail_late[data-1m]

I will try to find out more, but maybe others might already have an idea.

Best regards,

Rainer