Re: Unexpected HTTP status 400 'Bad request'.

Chris Capon <ttabyss_at_gmail.com> writes:

> What I don't know is how to diagnose the communications through apache
> and to the subversion server. No error messages appear in any of the
> apache2 logs nor the subversion log. So where is the error happening?

You should see the 400 in the apache logs at the very least, if apache
is not logging anything then you need to change LogLevel. The
Subversion regression tests generate a 400 and the apache log shows:

::1 - - [09/Dec/2015:09:44:28 +0000] "DELETE /svn-test-work/repositories/lock_tests-61/!svn/txr/2-2/A HTTP/1.1" 400 301 Length:-

[Wed Dec 09 09:29:40.749939 2015] [core:info] [pid 13733:tid 139669165561600] [client ::1:45002] AH00561: Request header exceeds LimitRequestFieldSize: If
[Wed Dec 09 09:29:40.749942 2015] [core:info] [pid 13733:tid 139669165561600] [client ::1:45002] AH00567: request failed: error reading the headers

There are various ways to trace the communication:
http://subversion.apache.org/docs/community-guide/debugging.html#net-trace
but these may not be useful if you are using https://. If you can
reproduce the problem for http:// it would be helpful.

If you can only use https:// one possibility is to use socat as an
http<->https relay:

  socat -v TCP6-LISTEN:9630,reuseaddr,fork OPENSSL:localhost:443,verify=0

Then use http:// to socat and have socat use https to apache:

  svn ls http://localhost:9603/...

-- 
Philip Martin
WANdisco