http: add CURLOPT_FAILON_STATUS and --fail-on-status - #20114

Analysis of PR #20114 at 49ede89a:

Test ../../tests/http/test_03_goaway.py::TestGoAway::test_03_02_h3_goaway failed, but it has been 0.7% flaky lately, so it's probably NOT a fault of the PR. Note that this test has failed in 2 different CI jobs (the link just goes to one of them).

Test 100 failed, which has NOT been flaky recently, so there could be a real issue in this PR. Note that this test has failed in 4 different CI jobs (the link just goes to one of them).

Test 101 failed, which has NOT been flaky recently, so there could be a real issue in this PR. Note that this test has failed in 4 different CI jobs (the link just goes to one of them).

Test 102 failed, which has NOT been flaky recently, so there could be a real issue in this PR. Note that this test has failed in 4 different CI jobs (the link just goes to one of them).

Test 103 failed, which has NOT been flaky recently, so there could be a real issue in this PR. Note that this test has failed in 4 different CI jobs (the link just goes to one of them).

Test 104 failed, which has NOT been flaky recently, so there could be a real issue in this PR. Note that this test has failed in 4 different CI jobs (the link just goes to one of them).

Test 105 failed, which has NOT been flaky recently, so there could be a real issue in this PR. Note that this test has failed in 2 different CI jobs (the link just goes to one of them).

There are more failures, but that's enough from Gha.

Generated by Testclutch

1. The TODO files speaks of a curl command line option. I'm not convinced libcurl needs this option.
2. I can imagine a common use case would be "treat everything except 200 an error". Should there be something for that?

should curl fail ONLY on status 204, or on status 204 IN ADDITION TO the other status codes

I think it needs to replace the other ones, otherwise you need a syntax to remove the default ones as well.

Thanks for your comments!

The TODO files speaks of a curl command line option. I'm not convinced libcurl needs this option.

Just to make sure I understand, would the alternative be using the CURLOPT_HEADERFUNCTION callback to check the status against the user-provided values, and if it's a fail, return CURL_WRITEFUNC_ERROR?

I can imagine a common use case would be "treat everything except 200 an error". Should there be something for that?

Hmm, I take it --fail-on-status 0-199,201-999 would be too verbose? Maybe the user could use some kind of operator like ! or * or something for the specific case of "anything but this is an error"? Like --fail-on-status !200?

Closing this as I couldn't find a way to make the new approach work.