#!/bin/sh

do_filename() {
        desc=$1
        postimage=$2

        rm -fr file-creation &&
        git init file-creation &&
        (
                cd file-creation &&
                git commit --allow-empty -m init &&
                echo postimage >"$postimage" &&
                git add -N "$postimage" &&
                git diff HEAD >"../git-$desc.diff"
        ) &&

        rm -fr trad-modification &&
        mkdir trad-modification &&
        (
                cd trad-modification &&
                echo preimage >"$postimage.orig" &&
                echo postimage >"$postimage" &&
                ! diff -u "$postimage.orig" "$postimage" >"../diff-$desc.diff"
        ) &&

        rm -fr trad-creation &&
        mkdir trad-creation &&
        (
                cd trad-creation &&
                mkdir a b &&
                echo postimage >"b/$postimage" &&
                ! diff -pruN a b >"../add-$desc.diff"
        )
}

do_filename plain postimage.txt &&
do_filename 'with spaces' 'post image.txt' &&
do_filename 'with tab' 'post    image.txt' &&
do_filename 'with backslash' 'post\image.txt' &&
do_filename 'with quote' '"postimage".txt' &&
expand add-plain.diff >damaged.diff ||
{
        echo >&2 Failed. &&
        exit 1
}