Q:

How to split an SVN folder into its own repository when it has been renamed?

I want to split a directory from a large Subversion repository to a repository of its own, and keep the history of the files in that directory.
I tried the regular way of doing it first
svnadmin dump /path/to/repo > largerepo.dump
cat largerepo.dump | svndumpfilter include my/directory >mydir.dump

but that does not work, since the directory has been moved and copied over the years and files have been moved into and out of it to other parts of the repository. The result is a lot of these:
svndumpfilter: Invalid copy source path '/some/old/path'

Next thing I tried is to include those /some/old/path as they appear and after a long, long list of files and directories included, the svndumpfilter completes, BUT importing the resulting dump isn't producing the same files as the current directory has.
So, how do I properly split the directory from that repository while keeping the history?
EDIT: I specifically want trunk/myproj to be the trunk in a new repository PLUS have the new repository include none of the other old stuff, ie. there should not be possibility for anyone to update to old revision before the split and get/see the files.
The svndumpfilter solution I tried would achieve exactly that, sadly its not doable since the path/files have been moved around. The solution by ng isn't accetable since its basically a clone+removal of extras which keeps ALL the history, not just relevant myproj history.

A:

I had a similar problem splitting a repository .. 
svndumpfilter: Invalid copy source path /dir/old_dir

What I did to get around the problem was to include the additional old directories that is was requesting, or that you know you moved. In my case I had moved 3 directories into another directory.
eg. Moved Folders A,B,C in to Folder D
cat project.dump | svndumpfilter include A B C D > new.dump

This seemed to solve my problem. I was able to separate Folder D from the rest of the Repo.
On the flip-side, when excluding D I did not get the error, I would guess because removing D didn't require the links/history to A,B,C

A:

This problem occurs when one of the directories/files included by svndumpfilter originally was copied or moved from a section of the tree that is not being included.
To solve the problem use this script: svndumpfilter3

A:

I've tried at least 4 different applications to do that, the only that really worked was using  svndumpfilterIN :
cd /usr/local/bin/
sudo wget --no-check-certificate https://raw.github.com/jasperlee108/svndumpfilterIN/master/svndumpfilter.py
sudo chmod +x svndumpfilter.py
# To be sure nothing will happened on the original repo :
cp -au /path/to/repo /tmp/largerepo.repo/
svnadmin dump /path/to/repo > /tmp/largerepo.dump
svndumpfilter.py /tmp/largerepo.dump --repo=/tmp/largerepo.repo --output-dump=/tmp/mydir.dump include my/directory

Here is what I tried and didn't worked :

http://furius.ca/pubcode/pub/conf/bin/svndumpfilter3.html (from previous answer)
Including the problematic path as said in another previous answer. Problem : I still have paths I do not want in the target dump
svndumpsanitizer (I still have paths I do not want in the target dump also)

