Tool to aid back-porting a dev->topic_branch onto a release->integration branch.

git-backport.sh

#!/bin/sh
# Backport a topic-branch based on a development line back to a release branch.
# Generally this is a proof-of-concept/notes on overall process.  Needs a number
# of sanity checks added before it is a real tool.
set -e
error() { echo "error: $*" >&2; }
die() { error "$*"; exit 1; }
## Update Branches
# FIXME we need to sanity check all the arguments
start="${1}"    # What rev to reset the target to before merging
from="${2}"     # Where to merge from
saved_cwd="${PWD}"
test -d "../${from}" || die "invalid worktree '${from}'"
set -- $(cd "../${from}" && git-branch-ancestry)
master="${1+master}"
# Use rebase to perform a type of cherry-pick which applies the string of
# revisions "onto" the target branch @ the start revision.
since="$(git merge-base --fork-point "${master}" "${from}")"
until="$(git rev-list --max-count=1 "${from}")"
git reset --hard "${start}"
onto="$(git symbolic-ref --short HEAD)"
git rebase --onto "${onto}" "${since}" "${until}"