Re: [PATCH v2 5/8] http: correct version check for CURL_HTTP_VERSION_2

On Fri, Sep 10, 2021 at 01:04:30PM +0200, Ævar Arnfjörð Bjarmason wrote:

In d73019feb44 (http: add support selecting http version, 2018-11-08)
a dependency was added on CURL_HTTP_VERSION_2, but this feature was
introduced in curl version 7.43.0, not 7.47.0, as the incorrect
version check led us to believe.

As looking through the history of that commit on the mailing list will
reveal[1], the reason for this is that an earlier version of it
depended on CURL_HTTP_VERSION_2TLS, which was introduced in libcurl
7.47.0.

But the version that made it in in d73019feb44 had dropped the
dependency on CURL_HTTP_VERSION_2TLS, but the corresponding version
check was not corrected.

The newest symbol we depend on is CURL_HTTP_VERSION_2. It was added in
7.33.0, but the CURL_HTTP_VERSION_2 alias we used was added in
7.47.0. So we could support an even older version here, but let's just
correct the checked version.

Thanks for expanding on the history here. I agree it probably doesn't
matter much between the two versions, as they're both 6+ years old (and
only about 6 months apart). If somebody has a case where it really
matters, they can submit a patch.

-Peff