git-transplant

git-transplant.sh

#!/bin/bash

if [ "$#" -lt 2 ]
then
  cat << EOM

  Usage: git-transplant <FROM> <TO> <UPSTREAM>

  Transplants <FROM> .. <TO> commit range (inclusive) on top of <UPSTREAM>.
  If <FROM> is a number, transplant that number of commits ending at <TO> instead
    (i.e. <TO>~<FROM> .. <TO> range).
  <UPSTREAM> defaults to current branch (HEAD).

EOM
  exit 1
fi

DEPTH=$1
TO=$2

if [ "$DEPTH" -eq "$DEPTH" ] 2>/dev/null
then
  FROM=$TO~$DEPTH;
else
  FROM=$DEPTH~1
fi

UPSTREAM=${3-HEAD}

BRANCH=$(git rev-parse --abbrev-ref $UPSTREAM)
ONTO=$(git rev-list $UPSTREAM --abbrev-commit -1)

echo -e "\nTransplanting $FROM..$TO onto $BRANCH (was at $ONTO)\n"

set -x
git checkout $TO
git branch -f $BRANCH
git rebase -i --onto $ONTO $FROM $BRANCH;
set +x

👍