#!/bin/bash
set -e

# stg-mdiff - display meta-diffs, ie. diffs of diffs

# Main use: show evolutions of a patch.
# eg. stg-mdiff foo@stable foo
#     stg-mdiff foo 012345567ABCD # sha1 for "foo" as integrated upstream

# Copyright (c) 2007 Yann Dirson <ydirson@altern.org>
# Subject to the GNU GPL, version 2.

usage()
{
    echo "Usage: $(basename $0) <from1>..[<to1>]|<patch1> <from2>..[<to2>]|<patch2>"
    exit 1
}

if [ "$#" != 2 ]; then
    usage
fi

case "$1" in
*..*) cmd1="stg diff" ;;
*)    cmd1="stg show" ;;
esac
case "$2" in
*..*) cmd2="stg diff" ;;
*)    cmd2="stg show" ;;
esac

colordiff -u <($cmd1 "$1") <($cmd2 "$2") | less -RFX