#!/bin/sh -e

[ -n "$1" ]
[ -e debian/rules ]
[ -d debian/patches ]
[ ! -e debian/patches/$1 ]

CWD=`pwd`
D=`mktemp -d`
trap "rm -rf $D" 0 1 2 3 4 5 6 7 8 10 11 12 13 14 15

debclean
cp -r . $D/orig
cd $D/orig
debian/rules setup || debian/rules patch || debian/rules apply-patches || debian/rules apply-dpatches || debian/rules unpack || debian/rules patch-stamp
[ -z "`find -name '*.rej'`" ] || {
    echo 'there are rejections from the current patches, aborting' >&2
    exit 1
}
find -name '*.orig' | xargs rm || true
cd ..
cp -a orig new
cd new
echo 'make your modifications in this shell and exit it successfully'
bash
find -name '*.orig' | xargs rm || true
cd ..
diff -Nurp orig new > "$CWD/debian/patches/$1"