How to synchronize a git repository with an unversioned folder

Question

I have a project that uses Git for version control.

It is based on an open source project, which is not managed with Git.

I start from a official release (say version 1.0) that I download from the project website (as a zip file).

In my repository, I add some files, modify others, delete some.

Then, the open source project releases a new version (say 2.0). I download the zip file and I want to synchronize it with my developments.

In this simple example, my development version of the software contains 3 files:

• new_dev.txt (a new file that exists in my development version, but not in the 2.0 release)

Content:

toto 1
toto 2
toto 3

• unmodified.txt (a file that has not been modified)
• modified.txt (a file that has been modified in my development version and in the 2.0 release)

Content:

line 1
line 2
line 30

The version 2.0 contains three files as well:

• unmodified.txt (same as the development version)
• new_release.txt (a file that is not in my developments but exists in the new release)

Content:

line 1
line 2
line 3

• modified.txt (a file that has been modified)

Content:

line 1
line 20
line 3

To merge my development version with the new release, I do the following:

• I create a new branch: git checkout -b v2.0
• I delete everything in it
• I copy/paste the version 2.0 files
• git add -A .
• git commit -m "v2.0"
• git checkout master
• git merge v2.0

The console output is the following:

Updating 54cf5a5..14725f2
Fast-forward
 modified.txt    | 4 ++--
 new_dev.txt     | 3 ---
 new_release.txt | 3 +++
 3 files changed, 5 insertions(+), 5 deletions(-)
 delete mode 100644 new_dev.txt
 create mode 100644 new_release.txt

The problems are:

• the file new_dev.txt has been deleted
• for file modified.txt, it kept the version 2.0 and did not merge my changes

What did I do wrong?

Is there a better way to achieve this?

Answer 1

I would follow this workflow to cope with the remote project not being versioned by Git:

• create a new local folder for the project and do git init
• download the entire project into this location
• git add all project files, commit, and then git push origin master
• git checkout -b yourBranch to create a new branch from the original project

You can now do all you work in yourBranch as you would in any other feature branch. You can't contribute back to the remote project via Git, so you will presumably not be merging back to master. When it is time to update your branch you can try the following

• git checkout master to switch to the master branch
• now copy the latest project files from the remote location
• do git add for each file which has changed, followed by git commit
• now switch to your branch via git checkout yourBranch
• merge the latest changes using git merge master

This strategy should work, but it has one caveat. As time goes on you run the risk of diverging further and further from the remote project, which does not know of your changes. It could get to the point where bringing in the latest changes to master and then merging could causs some ugly merge conflicts. The best long term solution might be to find a way to contribute to the remote project in both directions, either using Git or another versioning tool.