Is there a way to import svn history into git after the fact?

Question

I already have a svn read only repo checked out (svn co and not git svn). I have made some changes and commits using git which is then pushed up to github.

At this point, git does not have all of the history from svn. I was wondering if there was a way to extract and import this at this point.

The various git-svn guides show how to import a clean repo and transfer the history but not one that I can find that is already in use.

Answer 1

To complete Thilo's good answer, once you have imported the svn repo into a git one, you can add that git repository into yours with a script as detailed in merging in unrelated git branches

#!/bin/bash

set -e

if test -z "$2" -o -n "$3"; then
    echo "usage: $0 REPO BRANCHNAME" >&2
    exit 1
fi

repo=$1
branch=$2

git fetch "$repo" "$branch"

head=$(git rev-parse HEAD)
fetched=$(git rev-parse FETCH_HEAD)
headref=$(git rev-parse --symbolic-full-name HEAD)

git checkout $fetched .

tree=$(git write-tree)

newhead=$(echo "merged in branch '$branch' from $repo" | git commit-tree $tree -p $head -p $fetched)
git-update-ref $headref $newhead $head
git reset --hard $headref

Other methods includes:

• try a "simple" git pull REPO BRANCH
• using git grafts to restore svn merge history by creating a text file at .git/info/grafts, where each line contains a commit id followed by its parents. Your local repository will henceforth act as if that commit actually descended from both parents.

Answer 2

You will probably have to do an svn import into a fresh git repository, merge the two repositories (just add them together, it will probably complain about them being unrelated) and then rebase the changes you made unto the imported history.