git-lazyrebase

#!/bin/bash

# upstream=${2:-upstream/develop}
set -e
set -o pipefail
git diff --exit-code || ( echo "Can't rebase with differences" && exit 1 )
files=()
while [ -f "$1" ]
do
  files+=( "$1" )
  shift
done
remote=${1:-upstream}
refspec=${2:-develop}
shift 2
git fetch "${remote}"
for b in "${@}"
do
  diff="diff.${b//\//.}"
  echo -e "\n\nBegin rebase: ${b}\n\n"
  ( [ "$(git rev-parse --abbrev-ref HEAD)" = "${b}" ] || \
      git checkout "${b}" ) && \
    git diff | tee "${diff}" && \
    # Undo any changes that may have been done by the checkout
    git reset --hard && \
    git pull && \
    # git rebase "${upstream}"
    git rebase "${remote}/${refspec}" && \
    echo -e "\nPushing ${b}" && \
    ( git signpush &&
      ( [ "${#files[@]}" -eq 0 ] || \
        git rollback "${files[@]}" ) ) || \
    ( [ "${#files[@]}" -gt 0 ] && \
      git rollback "${files[@]}" && \
      git diff --exit-code && \
      git signpush --no-verify ) || \
    ( echo Failed && exit 1 )
  if [ -e "${diff}" ]
  then
    rm -fv "${diff}"
  fi
  git status
  if [[ "${b}" != "${refspec}" ]] &&
    git diff --quiet "${remote}/${refspec}"
  then
    echo
    echo "Identical to ${remote}/${refspec}. Delete, rename, or push manually."
    echo
    exit 1
  fi
done