Extract a branch from a repo into a separate Repo when the branch is unrelated to the original repo with zero common files. This preservers original author name and commit date and removes any conflicting files completely.

git-pluck-branch-as-separate-repo.sh

cd /Users/izhar/Sites/my-source-repo || exit

echo "Reset current branch to prevent checkout errors"
git reset --hard

echo "Checkout the branch to extract, assumed 'dev'"
git checkout dev

echo "Delete destination branch if exists, assumed 'dex'"
git branch -D dex

echo "Recreate an orphan branch for destination"
git checkout --orphan dex

echo "Reset destination branch to avoid any leftover untracked or ignored files"
git reset --hard

echo "Make an empty commit as git requires a parent commit for cherry pick"
GIT_AUTHOR_DATE="2023-05-23 00:00:00" GIT_COMMITTER_DATE="2023-05-23 00:00:00" git commit --allow-empty -m "Initial commit"

echo "Start picking commits"

# Change the commit ID (bf7242c23) below from where the cherry picking should start

git rev-list --reverse bf7242c23^..dev | while read -r commit; do
	echo "---------------------------------------------------------------------------------------------------"
	commit_date=$(git log -1 --pretty=format:%ci "$commit")
	commit_message=$(git log -1 --pretty=%B "$commit")
	author_name=$(git log -1 --pretty=format:%an "$commit")
	author_email=$(git log -1 --pretty=format:%ae "$commit")

	echo "Picking $commit  $commit_message"
	echo "Date: $commit_date"
	echo "Author: $author_name <$author_email>"

	GIT_AUTHOR_DATE="$commit_date" GIT_COMMITTER_DATE="$commit_date" git cherry-pick "$commit" || {
		git diff --name-only --diff-filter=U | xargs git rm
		git cherry-pick --continue || git cherry-pick --skip || exit
	}
done