#language en
<<TableOfContents>>

== Repository setup ==

To convert from the svn repository, first setup the git repository on the alioth servers as described at [[Games/VCS/git]]. Afterwards, do the following on your local machine.

{{{
git svn clone --no-metadata \
    svn://svn.debian.org/svn/pkg-games/packages \
    -T /trunk/<package> \
    --branches /branches/<package> \
    --tags /tags/<package> \
    <package>
}}}

=== Repository Setup notes ===
 * This will take some time depending on how many commits there are in the SVN repository.
 * If the svn repository doesn't contain a branches or tags section for the package, then you can omit the {{{--branches}}} or {{{--tags}}} options.
 * --authors-file= can '''and should''' be used to convert svn login to git style Foo Bar <foo@bar.org>. For that you can use this script: [[http://svn.debian.org/viewsvn/pkg-games/scripts/trunk/mkGitSvnAliasFile.pl?rev=8467&view=log]]

== Turn the 'tags' branches into git tags ==
This was copied from pkg-java's [[https://anonscm.debian.org/cgit/pkg-java/pkg-java-svn2git.git/tree/migrate-svn-repo-to-git|migrate-svn-repo-to-git]]
{{{
echo "Converting branches to tags..."
for branch in `git branch -r`; do
    if [ `echo $branch | egrep "tags/.+$"` ]; then
        version=`basename $branch`
        subject=`git log -1 --pretty=format:"%s" $branch`
        GIT_COMMITTER_DATE=`git log -1 --pretty=format:"%ci" $branch` \
            git tag -f -m "$subject" "debian/$(sanitize_version "$version")" "$branch^"
        git branch -d -r $branch
    fi
done

# Remove the remotes/origin/trunk reference
git branch -rd origin/trunk
}}}

== Merge svn branches ==

Now merge the branches from svn into the master branch.
{{{
$ git merge \
      $(find .git/refs/remotes -type f ! -regex '.*trunk$' ! -regex '.*trunk@[0-9]*$' \
      ! -regex '.*\/alioth\/.*' -print0 | \
      xargs -0 -r echo | sed 's|\.git/refs/||g')
}}}

== Import orig source ==

After fetching from the svn repository, it's now time to import the contents of the orig source.
## Thanks to Stefano Zacchiroli <zack@debian.org> for reporting this at DebianBug:471560.
{{{
$ git symbolic-ref HEAD refs/heads/upstream
$ git rm --cached -r .
$ git commit --allow-empty -m 'initial upstream branch'
$ git checkout -f master
$ git merge upstream
$ gbp import-orig --pristine-tar <path_to_orig_tarball>
}}}
Note: Using the {{{--pristine-tar}}} option is optional.

It is also possible (but optional) to import the upstream history to mimic the git-buildpackage setup, using these two snipets. First import the upstream tarballs matching "origUrl" and rebase the master branch onto it (this need to be done manually for every upstream tarball to be imported, to check everything is working fine):
{{{
commit=$(git log -1 --grep="origUrl" --format="%H" --reverse)
message=`git log -1 --format="%s" $commit`
echo "Merging $commit: $message"
version=`echo $message| sed 's/[a-zA-Z_ ]*//'`
echo $version
while [ ! -f ../pkg-games/tarballs/$package_$version.orig.tar.gz ] && read -p "File not found. Version?" version;
do
	echo "Looking..."
done
echo "Tarball $version found"	
gbp import-orig --pristine-tar --no-merge --no-interactive ../pkg-games/tarballs/$package_$version.orig.tar.gz
git checkout $commit^1
git merge upstream/$version --allow-unrelated-histories -m "Merge tag upstream/$version"
merge_commit=`git log -1 --pretty=format:"%H"`
git rebase -m --keep-empty -i --committer-date-is-author-date --onto $merge_commit $commit master
}}}

Then move the tags to the new master branch:
{{{
#!/bin/sh
for tag in $(git tag -l 'debian/*')
do
	old_commit=`git log -1 --pretty=format:"%H" $tag`
	old_message=`git log -1 --pretty=format:"%s" $tag`
	echo $old_message
	for new_commit in $(git log --pretty="%H" --grep="$old_message" master)
	do
		new_date=`git log -1 --pretty="%ad" $new_commit`
		old_date=`git log -1 --pretty="%ad" $old_commit`
		echo $old_date $new_date
		if [ "$new_date" = "$old_date" ]; then
			echo "Found $new_commit"
			GIT_COMMITTER_DATE=`git log -1 --pretty=format:"%ci" $tag` \
				git tag -f "$tag" $new_commit
		fi
	done
done
}}}

== Push changes ==

After this step, push the contents of your local repository.
{{{
$ git remote add alioth git+ssh://<username>@git.debian.org/git/pkg-games/<package>.git
$ git push alioth master
$ git push alioth upstream
$ git push alioth pristine-tar
$ git push alioth --tags
}}}
Note: Using a 'pristine-tar' branch is created only if you used the {{{--pristine-tar}}} option above.

This step here is a way to push the tags and branches that were imported from svn (an explanation about this is below). Do this to push all tags and branches that were imported.
{{{
$ for REMOTES in `find .git/refs/remotes -type f ! -regex '.*trunk$' \
      ! -regex '.*trunk@[0-9]*$' ! -regex '.*\/alioth\/.*'`; \
      do git push alioth $(echo $REMOTES | sed 's|\.git/refs/||'); done
}}}

||<tablestyle="width:65%;margin-left:35%;padding-left:30pt" style="border:1pt solid #b48;border-left:5pt solid #d4a">'''Editing note :''' Why perform this last step? git-svn will have created branches for every SVN branch, even deleted ones. Should deleted/abandoned branches always be merged?||

Once you have pushed all changes to the shared repository, move the packaging directory from trunk in svn so that no one continues to work on it there.

== Move old packaging directory to attic ==

Move the packaging directory in trunk to the attic section and leave an appropriate message.
{{{
$ svn mv svn+ssh://svn.debian.org/svn/pkg-games/packages/trunk/<package> \
      svn+ssh://svn.debian.org/svn/pkg-games/packages/attic/<package>-svn-save \
      -m "Moving <package> from trunk to attic. Please use git repository instead."
}}}

== Update .mrconfig ==

And, finally, add a new section for the new repo in the .mrconfig file from from our SVN trunk:
{{{
$ (echo "[<package>]" ; \
echo "checkout = git clone git://git.debian.org/git/pkg-games/<package>.git"; \
echo) >> /path/to/the/SVN/trunk/checkout/.mrconfig
$ svn ci -m "Add <package>'s git repo to the .mrconfig file" /path/to/the/SVN/trunk/checkout/.mrconfig
}}}

== Cloning and pulling ==
Anyone pulling from a converted repository will have two steps to perform.
The first step is the usual cloning.
{{{
$ git clone git+ssh://<username>@git.debian.org/git/pkg-games/<package>.git
}}}

And then the next step involves pulling the "remotes" branches and tags that were pushed.
{{{
$ cd <package>
$ git pull origin +refs/remotes/*:refs/remotes/*
}}}

=== Note about tags and branches ===
##This information was taken from http://wiki.debian.org/DebianInstaller/git-svn.
Tags and branches are preserved using what's called "git remotes". This means that there are no real git tags and branches visible, but that the SVN trunk, tags and branches are tracked as separate repositories. Downside is that you need to switch to to the remotes individually before you can update them.

All tags and branches are listed under {{{.git/refs/remotes/}}} and can be checked out, but it is somewhat confusing as all old schemes for using tags and branches are there too...

So to checkout a branch do the following.
{{{
$ git checkout remotes/<some_branch>
}}}

And for tags.
{{{
$ git checkout remotes/tags/<some_tag>
}}}

== Tips ==

=== Removing SVN metadata ===

If you do not initially use --no-metadata (perhaps you want to track the SVN repository for a while, or want to leave it in whilst you debug something) you can remove it later with

{{{
$ git filter-branch -f --msg-filter 'sed -e "/^git-svn-id:/d"'
}}}

You should not do this for a published repository. See the git-filter-branch(1) man page for more information. In particular for large histories the -d argument might be useful.

----
CategoryGit