Remove spurious commit parent pointer

Question

I imported a Bazaar repository into Git (using git bzr), but the resulting repository contains a spurious commit parent link:

Answer 1

You can do it manually using the git commit-tree internal command.

We want to edit the commit tagged 1.02-6 to remove the spurious parent pointer (to 56a2f3b5948ab54c9239c2b384a6ea9eb1f410c4).

First, read the information from the existing commit object:

user@host:/path/repo.git$ git cat-file -p 1.02-6 
tree c658aa1ebcf2bf2a607696c7868b875be72fb01f
parent 56a2f3b5948ab54c9239c2b384a6ea9eb1f410c4
parent 4e671bf1d2298729c9e5cfd8229051cfe2c40831
author James Damour (Suvarov454)  1146319620 -0400
committer Bazaar Package Importer  1146319620 -0400

The "main/" in the Section line of debian/control should be assumed.

Extract the commit message using git log --format=%B -n 1 1.02-6.

Now create a new commit with the same content (excluding the spurious parent link, and the committer info):

git log --format=%B -n 1 1.02-6 | \
    GIT_AUTHOR_NAME="James Damour (Suvarov454)" \
    GIT_AUTHOR_EMAIL="suvarov454@users.sourceforge.net" \
    GIT_AUTHOR_DATE="1146319620 -0400" \
    git commit-tree c658aa1ebcf2bf2a607696c7868b875be72fb01f \
        -p 4e671bf1d2298729c9e5cfd8229051cfe2c40831

This created a new commit, and printed its hash (cc32e66...). Now turn it into a new branch:

git checkout -b fixed_commit cc32e66

and rebase master onto the new branch:

git checkout master
git rebase fixed_commit

And we're done:

You probably want to delete the old branches and re-tag the appropriate commits.

---

Actually it might be easier to use git filter-branch --parent-filter. I haven't tried that.