#!/bin/sh
Usage() {
   cat <<EOF
Usage: ${0##*/} repo revno name
  cherry pick revno from trunk branch

  This takes care of getting the patch and pulling it into the local
  directory.

  End result is modified:
    debian/patches/\${revno}-\${name}
    debian/patches/series
EOF
}

[ $# -eq 3 ] || { Usage 1>&2; exit 1; }
[ "$1" = "--help" -o "$1" = "-h" ] && { Usage; exit 0; }

repo=${1}
revno=${2}
name=${3}

name=${name%.patch}
name=${name%.diff}

fname="${revno}-${name}.patch"

( cd "${repo}" && 
  set -e
  cat <<EOF
Author: $(bzr whoami)
Last-Update: $(date +%Y-%m-%d --utc)
Upstream: r${revno}
Description: cherry pick from ${revno}
EOF
  bzr log -r${revno}..${revno} | sed -e 's,^$,.,' -e 's,^, ,' &&
  bzr diff -p1 -r$((${revno}-1))..${revno} ) |
  quilt import -P "${fname}" /dev/stdin

[ $? -eq 0 ] || { echo "failed"; exit 1; }

cat <<EOF
now,
  quilt push
  quilt refresh
  bzr add debian/patches/series debian/patches/${fname}
  bzr commit debian/patches/series debian/patches/${fname}
EOF
