Remove commit from history without changing anything else (dates, committers)

Question

I expected this to be as easy as interactive rebase, but I've noticed that rebase changes commit dates and committers.

What would be the easiest way to remove a commit from history while leaving everything else the same?

Answer 1

git rebase has a -x/--exec option which can help.

You can add environment variables which will, for each commit in the rebase todo list, help to keep date/author unchanged:

I mention that in "git rebase without changing commit timestamps"

git rebase -i --committer-date-is-author-date \
 -x 'git config user.name "$(git show -s --format=%an $(git rev-parse HEAD))"' \
 -x 'git config user.email "$(git show -s --format=%ae $(git rev-parse HEAD))"' \
 @~x

(replace x in @~x by the number of commits you want your interactive rebase to start)

The problem is: you will need to manually copy those generated lines before the first pick todo item, in order for the first commit to use those settings.

Answer 2

I've tried multiple approaches using git rebase and git filter-branch, but neither worked. git filter-branch likely cannot work, since it operates on snapshots, while removing commits require operating on change-sets/patches.

The only solution that worked was to create my own rebase based on git cherry-pick:

# !!! Only do this when the working copy is clean !!!
git checkout --orphan new_branch
# Now clean up all the files
# !!! Careful !!!
# git reset --keep

git log --reverse --format=%H source_branch |
  grep -v -E "sha1|sha2|sha3" |
  while read sha; do
   (
    echo "Cherry-picking $(git show --no-patch --format=oneline "$sha")"
    export GIT_COMMITTER_NAME=$(git show -s --format=%cn "$sha")
    export GIT_COMMITTER_EMAIL=$(git show -s --format=%ce "$sha")
    export GIT_COMMITTER_DATE=$(git show -s --format=%cd "$sha")
    git cherry-pick "$sha" -Xtheirs
   )
  done