test798: force IPv4 to avoid cross-runner port aliasing

`test798` is the only test fetching `http://localhost:%HTTPPORT` without
`-4`, since it needs the hostname for its folded `domain=localhost`
cookie. curl tries `::1` first, but the test HTTP server is IPv4-only.
On the BSDs, IPv4 and IPv6 have separate ephemeral port namespaces, so
with every test server binding port 0, another parallel runner's
IPv6-bound server can hold the same numeric port. curl then connects to
the wrong runner's server, which cannot open its own `log/N/test798` and
closes without a response, giving exit 52 and an empty `server.input`.

This PR fixes this flake by adding `-4` matches what tests 389 and 392
already do. Linux is immune because wildcard IPv6 binds occupy the IPv4
port too. Seen in
https://github.com/curl/curl/actions/runs/29229170329/job/86749470571.

Closes #22318

diff --git a/tests/data/test798 b/tests/data/test798
index c69461ead714c9fdc53d8018c513eecdfdb15e0a..b3937e5713997f34053aff53b446e5537868f846 100644 (file)
--- a/tests/data/test798
+++ b/tests/data/test798
@@ -36,7 +36,7 @@ http
 HTTP cookies in a folded header
 </name>
 <command>
-http://localhost:%HTTPPORT/we/want/%TESTNUMBER -b none -c %LOGDIR/jar%TESTNUMBER.txt
+-4 http://localhost:%HTTPPORT/we/want/%TESTNUMBER -b none -c %LOGDIR/jar%TESTNUMBER.txt
 </command>
 <features>
 cookies