Re: [PATCH 2/3] http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION

On Sun, Jan 15, 2023 at 01:45:39PM -0800, Junio C Hamano wrote:

Jeff King [off-list ref] writes:

quoted

The IOCTLFUNCTION option has been deprecated, and generates a compiler
warning in recent versions of curl. We can switch to using SEEKFUNCTION
instead. It was added in 2008 via curl 7.18.0; our INSTALL file already
indicates we require at least curl 7.19.4.
...
+	if (offset < 0 || offset >= buffer->buf.len) {
+		error("curl seek would be outside of buffer");
+		return CURL_SEEKFUNC_FAIL;
 	}
+
+	buffer->posn = offset;
+	return CURL_SEEKFUNC_OK;
 }

Now we depend on having at least cURL 7.19.5 because
CURL_SEEKFUNC_{FAIL,OK} are not available before that version.

cf.  https://github.com/curl/curl/blob/master/docs/libcurl/symbols-in-versions#L127

Ugh. I did not even check that, because why would anyone introduce the
return values in a separate version! ;)

Which is fine, as 7.19.5 is from May 2009 that is old enough.  We
just need to update the place where you got the 7.19.4 above from.

OK, if we are all right with bumping the version, I can squash that in.
The other option is to fall back to the obvious 0/1 for OK/FAIL, which
is what curl does. But that feels awfully hacky, and it would only be
used if you were at _exactly_ 7.19.4. So I prefer the bump if it's
acceptable.

diff --git a/INSTALL b/INSTALL
index 3344788397..d5694f8c47 100644
--- a/INSTALL
+++ b/INSTALL

@@ -139,7 +139,7 @@ Issues of note:
 	  not need that functionality, use NO_CURL to build without
 	  it.
 
-	  Git requires version "7.19.4" or later of "libcurl" to build
+	  Git requires version "7.19.5" or later of "libcurl" to build
 	  without NO_CURL. This version requirement may be bumped in
 	  the future.
 

-Peff