#!/usr/bin/env bash
# Given a git hash ($1),
# use vimdiff to compare given commit to commit it was cherry-picked from.
#
# Author: Tom Saeger <tom.saeger@gmail.com>
# 6/21/2017

FIRST=${1:-$(tig-pick)}
SECOND=${2:-$(git show --format=email "${FIRST}" | sed -ne '/cherry picked/{s/.*commit \([0-9a-z]\+\).*/\1/;p;q;}')}

# if not "cherry picked" find first line with "commit"
if test -z "${SECOND}" ; then
SECOND=$(git show --format=email "${FIRST}" | sed -ne '/commit /{s/.*commit \([0-9a-z]\+\).*/\1/;p;q;}')
fi

if test -z "${SECOND}" ; then
    exit 0;
fi
vim -d <(git show --format=email "${FIRST}") <(git show --format=email "${SECOND}")