# Settings appropriate for patchsyncs of distributed patches of rsync

function was_patching_inexact {
	exec 3>&2
	code=0
	[ -n "$(find $1/ '(' -name '*.rej' -or -name '*.orig' ')' -printf 'Existence of file %P in branch indicates inexact patching\n' 2>&1 | tee /dev/fd/3)" ] && code=1
	[ "$code" == 1 ] && cat 1>&2 <<EOF
To avoid modifying the patch to fit the trunk behind your back,
I will refuse to diff until you remove the *.rej and *.orig files from the branch.
EOF
	exec 3>&-
	return $code
}

function do_patch {
	# Warn the user of inexactness, but it isn't an error yet
	exitoneok patch --backup-if-mismatch -d $2/ -p1 <$1 && ( was_patching_inexact $2 || true )
}

function do_diff {
	# Use the same format as verify-patches.
	# Use sed to carry over the portion of the old patch before the first `--- old/foo'.
	was_patching_inexact $2 &&
	sed -e '/^--- /,$d' patch >$3 &&
	ln -nfs $1 old &&
	ln -nfs $2 new &&
	LC_COLLATE=C exitoneok diff -duprN old new | \
		sed -re 's/^(\+\+\+|---) ([^\t]+).*$/\1 \2/' | \
		exitoneok grep -v '^diff' | \
		tee --append $3 | \
		sed -nre 's/^(Binary files .* differ)$/\1; this is an error because the patch cannot represent this difference/p' >&2 &&
	rm -f old new
}