Git push master only after given commit

Question

I have a local git project that I would like to open source by pushing to a public Github repo. Let say that this is the local project history:

          F-G [feature-1]
         /   \
A-B-C-D-E     H-I-J   [master]
        ^
         \(first public ready commit) 

However, I have a problem: during prototyping I've hard-coded some sensitive data in. Let's say that up to commit D there's data in the code that I would not like anyone to see.

How can I preserve the change history in my local repo but only publish from E onwards?

I'm considering two approaches:

1. Squash the commits before E, which would make E the initial release.
2. Make some sort of publish branch that would begin a bit later that the master.

Command line snippets welcome!

Answer 1

In this case, I'd do it with a graft file and rewriting:

First, tag D and E. I'll assume they can be referred to as D and E from here on.

Now, fake E's history so that it doesn't have a parent:

git rev-parse E >.git/info/grafts

Then, rewrite the commits to reflect this history:

git filter-branch -- --all

Now, you have a local tag D that points to the sensitive data, and a local tag E that points to the clean data as the initial commit:

  F'-G' [feature-1]
 /     \
E'      H'-I'-J'   [master]

A-B-C-D

Now, for your local needs, it may be helpful to have E' show D as the parent again, and this can be done with a graft file again:

echo `git rev-parse E` `git rev-parse D` >.git/info/grafts

Note that you don't want to run git filter-branch now.

Locally, your history will look like this:

          F'-G' [feature-1]
         /     \
A-B-C-D-E'      H'-I'-J'   [master]

but if you push, you'll push the real E', which has no parent, so remotely, you'd only get

  F'-G' [feature-1]
 /     \
E'      H'-I'-J'   [master]