Move files to a trash branch

git-trash.sh

#!/bin/bash
set -e

error(){
  echo "$@" >>/dev/stderr
  exit 1
}

GIT_TRASH_FILE=.git/trash.idx
remotes=(origin)
files=("$@")

[ -e .git ] || error ".git does not exists"
[ ! -e "$GIT_TRASH_FILE" ] ||
   { cat <<EOF
$GIT_TRASH_FILE already exists. Check that not other instance of git-trash is
running. It might also be the case that this file is used by another program
or that git-trash died without cleaning this file away.
EOF
     exit 1
   }

intrash(){
  GIT_INDEX_FILE="$GIT_TRASH_FILE" "$@"
}

# Create an empty branch called 'trash' (no files except one called README.git-trash)
# if no such branch exists.
if git rev-parse -q --verify refs/heads/trash; then
  :
else
  for r in "${remotes[@]}"; do
    if git rev-parse -q --verify "$r"/trash; then
      git update-ref refs/heads/trash "$r"/trash
      break
    fi
  done
  if git rev-parse -q --verify refs/heads/trash; then
    :
  else
    # Creating a new trash branch.
    intrash git read-tree --empty
    tree=$(intrash git write-tree)
    head=$(echo "Init trash" | intrash git commit-tree "$tree")
    git update-ref refs/heads/trash "$head"
  fi
fi

msg='Put some files to the trash branch'

intrash git read-tree refs/heads/trash
intrash git add "${files[@]}"
tree=$(intrash git write-tree)
head=$(echo "$msg" | intrash git commit-tree "$tree" -p refs/heads/trash)
rm $GIT_TRASH_FILE
git update-ref refs/heads/trash "$head"
git rm "${files[@]}"
git commit -m"$msg" "${files[@]}"