apatch/apatch

#!/bin/sh

cleanup() {
  rm -rf src-old
}

trap 'cleanup' EXIT INT HUP

startdir="$PWD"

[ -f APKBUILD ] || ( echo "please run this in a package directory"; exit 1 )
[ "$1" != "" ] || ( echo "usage: apatch <patch name>"; exit 1 )

abuild clean fetch unpack prepare || exit 1

# obtain builddir
. APKBUILD
[ -z "$builddir" ] && builddir="/$pkgname-$pkgver"

cp -r src src-old

for patch in $source; do
  if [ "$patch" = "$1" ]; then
    # if the patch was in source, it was already applied in prepare() above,
    # but we want the original src to not have it, so we can get a full diff of
    # its original changes + our new ones
    (
      cd "src-old/$builddir"
      patch -R -p1 < "$startdir/$1"
    )
    break
  fi
done

(
  cd "src$builddir"
  $SHELL
)

busybox diff -N -U3 -r "src-old$builddir" "src$builddir" | sed "s|src-old$builddir|a|g;s|src$builddir|b|g" > $1