Dump filter correcting svn:mergeinfo

Similar to my other post about "Dump filter correcting EOL style"
[1] I'm seeking for dump filters correcting number of
inconsistencies caused by improper Subversion use.

Has someone come up with a repository dump filter which corrects
svn:mergeinfo [1] data by consolidating repeated merge info on
sub-directories and files only to the root project directory (i.e.
"trunk" and "branches/<name>") and cleaning that repeated info from
the sub-directories and files? I know this could be tricky but I
would like to try any somewhat working solutions/filters.

[1]
<http://mail-archives.apache.org/mod_mbox/subversion-users/201104.mbox/%3C4DB16855.1060700@netscape.net%3E>
[2]
<http://svnbook.red-bean.com/nightly/en/svn-book.html#svn.branchmerge.basicmerging.mergeinfo>

-- 
Stanimir