[PATCH 0/3] remote-curl smart-http discovery cleanup

From: Jeff King <peff@peff.net>
Date: Nov 16, 2018, 08:44 UTC
Message-ID: <20181116084427.GA31493@sigill.intra.peff.net>
In-Reply-To: <20181115215152.GK126896@google.com>

On Thu, Nov 15, 2018 at 01:51:52PM -0800, Josh Steadmon wrote:

Show 17 quoted lines

> > This patch tightens both of those (I also made a few stylistic tweaks,
> > and added the ERR condition to show where it would go). I dunno. Part of
> > me sees this as a nice cleanup, but maybe it is better to just leave it
> > alone. A lot of these behaviors are just how it happens to work now, and
> > not part of the spec, but we don't know what might be relying on them.
> 
> At least according to the protocol-v2 and http-protocol docs, the
> stricter behavior seems correct:
> 
> For the first point above, dumb servers should never use an
> "application/x-git-*" content type (http-protocol.txt line 163-167).
> 
> For the second point, the docs require v2 servers to use
> "application/x-git-*" content types. protocol-v2.txt lines 63-65 state
> that v2 clients should make a smart http request, while
> http-protocol.txt lines 247-252 state that a smart server's response
> type must be "application/x-git-*".

Thanks for digging into the spec. I agree that it's pretty clear that the appropriate content-type is expected.

> Of course we don't know if other implementations follow the spec, but
> ISTM that this patch at least doesn't contradict how we've promised the
> protocols should work.

These seem like pretty unlikely ways for a buggy server to behave, so I think it's a reasonable risk. I also checked GitHub's implementation (which recently learned to speak v2) and made sure that it works. :) I didn't check JGit, but given the provenance, I assume it's fine.

Amusingly, this does break the test you just added, because it tries to issue an ERR after claiming "text/html" (and after my patch, we correctly fall back to dumb-http).

> If no one has any objections, I'll include the diff below in v2. Thanks
> for the help Jeff!

I think it makes sense to do the refactoring first as a separate step. And of course it needs a commit message. So how about this series (your original is rebased on top)?

  [1/3]: remote-curl: refactor smart-http discovery
  [2/3]: remote-curl: tighten "version 2" check for smart-http
  [3/3]: remote-curl: die on server-side errors

 remote-curl.c                   | 96 +++++++++++++++++++++------------
 t/lib-httpd.sh                  |  1 +
 t/lib-httpd/apache.conf         |  4 ++
 t/lib-httpd/error-smart-http.sh |  3 ++
 t/t5551-http-fetch-smart.sh     |  5 ++
 5 files changed, 75 insertions(+), 34 deletions(-)
 create mode 100644 t/lib-httpd/error-smart-http.sh

-Peff