Error leak leads to confusing place

Saw some "Aborted" message today trying to use a 1.6 client on a trunk
working copy. When I explored the cause, I found a leaked error was to
blame. If you read subversion/libsvn_wc/lock.c:do_open(), you see this
chunk of code (minus the line I'm showing that I added to fix the problem).

  if (! under_construction)
    {
      err = svn_wc_check_wc(path, &wc_format, subpool);

      if (wc_format == 0 || (err && APR_STATUS_IS_ENOENT(err->apr_err)))
        {
          return svn_error_createf(SVN_ERR_WC_NOT_DIRECTORY, err,
                                   _("'%s' is not a working copy"),
                                   svn_path_local_style(path, pool));
        }
+ SVN_ERR(err);
    }

Of course, I was working backwards here, finding a bugfix on the branch and
then looking for the same bug in trunk so I can commit the fix there and
suggest backport. What I find is (surprise, surprise) that the WC code
looks drastically different. I'm pretty sure that the matching chunk of
code is this bit from open_single():

  SVN_ERR(svn_dirent_get_absolute(&local_abspath, path, scratch_pool));
  err = svn_wc__internal_check_wc(&wc_format, db, local_abspath, scratch_pool);
  if (wc_format == 0 || (err && APR_STATUS_IS_ENOENT(err->apr_err)))
    {
      return svn_error_createf(SVN_ERR_WC_NOT_DIRECTORY, err,
                               _("'%s' is not a working copy"),
                               svn_path_local_style(path, scratch_pool));
    }
  svn_error_clear(err);

This code doesn't leak the error like the 1.6.x branch code does, though.
So that's a good thing. But I noticed that rather than raise 'err' as I'd
expect, trunk just clears it with no nearby comment explaining why it's okay
to do that.

Does anyone know the reason why?

What should be done for 1.6.x in terms of fixing this?

-- 
C. Michael Pilato <cmpilato_at_collab.net>
CollabNet   <>   www.collab.net   <>   Distributed Development On Demand
------------------------------------------------------
http://subversion.tigris.org/ds/viewMessage.do?dsForumId=462&dsMessageId=2354191