# Separating multiple SVN projects into individual Hg repositories

If you have a Subversion repository setup with multiple top-level projects and their typical  branches/tags/trunk setup and want to migrate these to individual Mercurial (Hg) repositories, you can do this with the convert extension.

First you need to enable convert in your .hgrc by adding a section like the following:

[extensions] convert =

Next, if needed, create a plain-text file, e.g. author-map.txt, containing SVN username to Hg author mappings, e.g. asmodai=Jeroen Ruigrok van der Werven <email@address.tld>.

Next run Hg as follows:

hg --authors author-map.txt --config convert.svn.branches=project/branches --config convert.svn.tags=project/tags --config convert.svn.trunk=project/trunk path/to/svn/repository path/to/destination/hg/repository

This will start a SVN to Hg conversion, picking up only the changes and commit messages applicable for the various paths you gave for the branches, tags, and trunk, effectively splitting off this project from the main SVN tree into its own Hg repository.

Do note that for large SVN repositories this might not be the most efficient conversion way forward. In that case converting once from SVN to Hg and then split off Hg into many Hg repositories might be faster. Will adjust this post when I write that up.

# TortoiseSVN (Subversion) and Windows 7 file corruption

During a checkout of a Subversion tree on my Windows 7 installation I got quite a fair share of errors from TortoiseSVN, all of which ended with The file or directory is corrupted and unreadable.

After digging around a bit, I came across this blog post on the exact same problem. And subsequently I found there is a hotfix available from Microsoft on their page about . This hotfix will be in the upcoming service pack 1.

You might also be able to work around it by disabling indexing on the particular folder or drive. It solved it for me at least.

# OpenSSH ControlMaster and Subversion

OpenSSH has a fantastic feature called ControlMaster. Basically this option allows you to create a socket that will share your already opened ssh session to the same host. To enable this option for all you put the following snippet in your $HOME/.ssh/config after creating something like $HOME/.ssh/sockets:

Host *
ControlMaster auto
ControlPath ~/.ssh/sockets/%r@%h:%p

For every username@host:port it will create a socket in $HOME/.ssh/sockets. The only problem is that current Subversion (1.4.6 on my FreeBSD box) cannot work well with control sockets when using the svn+ssh:// URI identifier. In order to work around this problem you can add a specific host before the wildcard entry, for example: Host svn.example.com ControlMaster no Host * ControlMaster auto ControlPath ~/.ssh/sockets/%r@%h:%p Of course, doing it like this is a bit tedious for every Subversion repository you use in this manner. Thankfully there is another way to do this. In $HOME/.subversion/config there is a section called [tunnels]. If you add the following entry to that section it will disable the ControlMaster:

[tunnels]
ssh = ssh -o ControlMaster=no