Hello,
I’m trying to do a one-time conversion of a large SVN repository to git using git-svn. Unfortunately, this SVN repo contains a substantial amount of non-standard branches created from a subfolder of trunk/. Users that only need to work on part of the code inside the repo usually create such branches to avoid having to download unneeded files.
A toy example showing what I’m talking about:
trunk/
- subfolder1/
- …
- subfolder2/
- …
branches/
- branch1/ (initially cp’ed from trunk/subfolder1)
- …
- branch2/ (initially cp’ed from trunk/subfolder2)
- …
- branch3/ (initially cp’ed from trunk)
- …
While in my experience, git-svn is able to correctly handle branches/branch3, it fails on branch1 and branch2. By "fails" I mean that it still performs the conversion, but any relationship to the trunk is completely missing. Instead, in the resulting git repository it looks like those branches have a completely separate history, starting from nothing.
Is there any way to fix such branches from subfolders in a way that they integrate correctly with the converted git repository, without losing any (or at least too much) history? If this is not possible with git-svn directly, maybe I could prepare the SVN repo or post-process the converted git repository somehow?
Thanks!
Am 19.08.2017 um 14:45 schrieb Jan Teske:
Is there any way to fix such branches from subfolders in a way that they integrate correctly with the converted git repository, without losing any (or at least too much) history? If this is not possible with git-svn directly, maybe I could prepare the SVN repo or post-process the converted git repository somehow?
You can use `git replace --graft` to connect the first commit of the
loose branches with their source. After all connections are in place you
can use `git filter-branch` to make the replacements permanent.
This will not change the content or directory structure of branch1 or
branch2 but the diff with their parent commits will show up as a huge
delete/rename operation. So merging/Cherry-picking between trunk and
branch1/branch2 will be ... challenging.
On 20. Aug 2017, at 12:27 , Andreas Heiduk [off-list ref] wrote:
Am 19.08.2017 um 14:45 schrieb Jan Teske:
quoted
Is there any way to fix such branches from subfolders in a way that they integrate correctly with the converted git repository, without losing any (or at least too much) history? If this is not possible with git-svn directly, maybe I could prepare the SVN repo or post-process the converted git repository somehow?
You can use `git replace --graft` to connect the first commit of the
loose branches with their source. After all connections are in place you
can use `git filter-branch` to make the replacements permanent.
This will not change the content or directory structure of branch1 or
branch2 but the diff with their parent commits will show up as a huge
delete/rename operation. So merging/Cherry-picking between trunk and
branch1/branch2 will be ... challenging.
That’s really helpful, thanks!
I even solved the problem of the challenging merging between the converted branches and trunk by using another filter-branch to rewrite all the commits in branch1/branch2 to make all their modifications in the respective subfolders (effectively fixing the directory structure to fit trunk). This answer was helpful for how to do this: https://unix.stackexchange.com/a/280229
So, for future reference, the following post-processing seems to work:
1. Use filter-branch to move all the commits the the correct subfolder.
2. Use `git replace --graft` to connect the first commit of the branch to its correct parent commit.
3. Use `git replace --graft` to add the missing parents of any merge commits the branch was part of.
4. Use filter-branch again to make the replacements permanent.