git-repo-zipper

Merges multiple Git repositories in a zipper-like style.

How it works

Given you have multiple repositories with roughly the same branch structure, git-repo-zipper will merge the repositories by cherry-picking the commits on each other (determined by commit date) to produce a single repository. Think of it like a zipper for git repositories:

Repository A:

       A4----A5----A7 topic
      /             \
A1---A2---A3---A6---A8 master

Repository B:

       B4----B5----B7 topic
      /        \    \
B1---B2---B3---B6---B8 master

Merged Repository:

       B4-----A4----A5-----B5-------B7---A7 topic
      /                      \        \    \
B1---A1---A2---B2---B3---A3---B6---A6---B8---A8 master

Zipping also works with more than two input repositories.

Usage

git-repo-zipper is written in C# and should run on Linux, Max and Window using either Mono or the original Microsoft .NET Framework.

Synopsis

  -o, --output    Required. The output repository to write to.

  -i, --input     The input repositories to read from.

  -f, --force     (Default: False) Forces overriding the output repository.

  -k, --keep      (Default: False) Keeps the remotes to the input repositories.

  --help          Display this help screen.

If you get an error like System.TypeInitializationException: The type initializer for 'LibGit2Sharp.Core.NativeMethods' threw an exception. ---> System.DllNotFoundException: NativeBinaries/linux/amd64/libgit2-785d8c4.so (especially on Linux), ensure to preload an older version of libcurl:

   LD_PRELOAD=libcurl.so.3

This is acurrent limitation of libgit and has to be fixed upstream.

Prerequisites

• All repositories have a similar branch structure, essentially the same branch names in order to get zipped
• Branches should have been created at the same time for all repositories

Limitations

The zipper works best repositories exported directly from Subversion (this was my use-case), this implies these limitations:

• The input repositories must start from one root commit
• Anonymous branches are not migrated (yet)
• Tags will not be converted (yet)

The zipper might still work in these cases, but please validate the result. However, this holds in general. If you encounter a limitation or bug, feel free to open an issue or pull request.

Build & Test

The project is built using the provided solution in the repository root. Use either an IDE (MonoDevelop, XamarinStudio, VisualStudio) or XBuild/MSBuild on the terminal and ensure nuget packages are restored beforehand. Tests are written with NUnit2 and should run from the terminal as well as from the IDE. See .travis.yml for further information.