Problems accessing GitHub's SVN-bridge with SVN 1.11

[Branko Čibej]

Guten Tag Branko Čibej,

I'm not sure what you mean by "handles more than only DAV successfully"

I thought it might be possible that GitHub answers differently but
properly, because the other check mentioned something about HTTP v2.
Because of TLS, I was unable to look at the requests and responses
then, but it's like you said, they don't provide DAV-headers in their
response to OPTION.

And yes, the HTTP/DAV specification requires that header to be present
in the response.

Which you didn't care about before and things worked for some years
for some users.

We made this change because users complained about unhelpful error
messages when they tried to connect to a server that did not even
implement HTTP/DAV. The error message was "Malformed XML in response"
which wasn't exactly helpful for diagnosing the problem.
I admit I didn't have GitHub in mind when I added this check. ...

svn info https://github.com/apache/subversion/trunk
It runs on one of our build slaves, so we'll know fairly soon when (if)
GitHub deploys a fix. And, of course, we'll also know if this feature
breaks again in future.
http://svn.apache.org/r1845942

I created SVN-4789 to track this and added a patch with a possible fix.
I did not commit it because it contains what is, in my opinion, a really
horrible hack; but it does let our client work against
https://github.com again. I would very much prefer that GitHub adds that
trivial one-liner fix to their bridge implementation. However, if this
issue persists and prevents users from migrating to 1.11.x and later, we
may have to use this hack under protest. Note that it is in some ways
similar to the now-defunct ASP.NET hack.

[[[
Hack ra_serf to work with GitHub's bridge again.

* subversion/libsvn_ra_serf/options.c
(options_context_t): New member 'received_github_request_id_header'.
(capabilities_headers_iterator_callback): Check if we received that header.
(options_response_handler): Allow DAV responses without DAV headers, if
the 'X-GitHub-Request-Id' header is present.

* subversion/tests/cmdline/dav_tests.py
(connect_to_github_server):
Remove the @XFail annotation. Add an @Issue annotation.
Change the test URL to point at HTTPd's GitHub mirror.

Issue: SVN-4789
]]]


-- Brane

[Branko Čibej]

Post by Branko Čibej

Guten Tag Branko Čibej,

I'm not sure what you mean by "handles more than only DAV successfully"

I thought it might be possible that GitHub answers differently but
properly, because the other check mentioned something about HTTP v2.
Because of TLS, I was unable to look at the requests and responses
then, but it's like you said, they don't provide DAV-headers in their
response to OPTION.

And yes, the HTTP/DAV specification requires that header to be present
in the response.

Which you didn't care about before and things worked for some years
for some users.

We made this change because users complained about unhelpful error
messages when they tried to connect to a server that did not even
implement HTTP/DAV. The error message was "Malformed XML in response"
which wasn't exactly helpful for diagnosing the problem.
I admit I didn't have GitHub in mind when I added this check. ...

svn info https://github.com/apache/subversion/trunk
It runs on one of our build slaves, so we'll know fairly soon when (if)
GitHub deploys a fix. And, of course, we'll also know if this feature
breaks again in future.
http://svn.apache.org/r1845942

I created SVN-4789 to track this and added a patch with a possible fix.
I did not commit it because it contains what is, in my opinion, a really
horrible hack; but it does let our client work against
https://github.com again. I would very much prefer that GitHub adds that
trivial one-liner fix to their bridge implementation. However, if this
issue persists and prevents users from migrating to 1.11.x and later, we
may have to use this hack under protest. Note that it is in some ways
similar to the now-defunct ASP.NET hack.
[[[
Hack ra_serf to work with GitHub's bridge again.
* subversion/libsvn_ra_serf/options.c
(options_context_t): New member 'received_github_request_id_header'.
(capabilities_headers_iterator_callback): Check if we received that header.
(options_response_handler): Allow DAV responses without DAV headers, if
the 'X-GitHub-Request-Id' header is present.
* subversion/tests/cmdline/dav_tests.py
Change the test URL to point at HTTPd's GitHub mirror.
Issue: SVN-4789
]]]

Actually the attached updated patch is a bit more to my taste.

-- Brane