Svn merge using only working copy paths

Hi,
In an attempt to make svn merge perform better I am trying to do the merge using only local paths. Not sure if this can help but I thought it wouldn't hurt to try. But now it seems this is not possible because of what looks like a bug to me. In any case I can't explain it and the help does not help at all and adds to the confusion.

For example when looking at help text like
     SOURCE is usually a URL. The optional '@REV' specifies both the peg
     revision of the URL and the latest revision that will be considered
     for merging; if REV is not specified, the HEAD revision is assumed. If
     SOURCE is a working copy path, the corresponding URL of the path is
     used, and the default value of 'REV' is the base revision (usually the
     revision last updated to).

The help suggests it is possible to use a working copy path as the SOURCE. Note also the remark about REV defaulting to base revision. Make sense but when I try

E:\New folder (2)\wedo2\dev\epic-1\done>svn merge "E:/New folder (2)/wedo2/dev/epic-1/work" "E:/New folder (2)/wedo2/dev/epic-1/done" --dry-run
svn: E195002: Invalid merge source 'E:\New folder (2)\wedo2\dev\epic-1\work'; a working copy path can only be used with a repository revision (a number, a date, or head)

The message suggests that base revision is not default. Maybe the help is not correct.

Next I try
E:\New folder (2)\wedo2\dev\epic-1\done>svn merge "E:/New folder (2)/wedo2/dev/epic-1/work_at_head" "E:/New folder (2)/wedo2/dev/epic-1/done" --dry-run
svn: E195002: Invalid merge source 'E:\New folder (2)\wedo2\dev\epic-1\done'; a working copy path can only be used with a repository revision (a number, a date, or head)

This is a bit unexpected. By adding @head or @HEAD or even only @ the 'second' path is no longer regarded as a TARGET_WCPATH. It has become a 'invalid merge source' and it is missing the 'repository revision'.

What am I missing here? Is this is a bug?
Thanks and Regards,
Onno

I am using SVN version 1.8.8 (r1568071
Received on 2014-03-10 11:12:22 CET