Logging of subrequest authorization checks in mod_dav_svn/mod_authz_svn

When doing operations like 'svn log' or 'svn ls' Subversion hides
paths that are unreadable for user.

I.e. if repository contains the following directories:
/public
/private

And authorization file looks like this:
[/]
* = r
[/private]
* =

Then 'svn ls REPOROOT' command will return only /public directory. The
'svn log' command does the same. So from the user prespective the
/private directory does not exist.

The problem is that Subversion 1.8.x always logs an error for *every*
access check for unreadable path.This result in thousands of error log
messages for one request, even if user didn't tried to access
unreadable path directly. In trunk (r1562417) behavior were slightly
changed and all "access denied" messages now logged with 'warning'
level instead of 'error'.

But I'm not sure that current behavior is the best. I'm thinking to
implement the following logic in mod_authz_svn: use different log
level whether access denied for subrequest or for primary request (the
URL user actually tried to access).

Does it make sense?

The other open question is which error level use for these 'soft'
access denied messages:
a) info (Like we do for access granted messages)
b) warning

I would like to resolve this problem before the 1.9 branch. The patch
should be simple, but I need help from the community to make this
decision.

Thoughts?

-- 
Ivan Zhakov