#!/bin/sh

set -eu
usage="Store the contents of ORIGINIAL as a new revision in RCSFILE.  Then,
maintain a checked-out list of the four most recent verisons, named
DIR/YYYY-MM-DD.SUFFIX, where YYYY, MM and DD are from ORIGINAL's
modification time."
eval "$(args rcs-stash original rcsfile dir suffix -- "$@")"

case "$rcsfile" in
    *",v" ) ;;
    * )
    echo "rcs-stash: not an RCS ,v file: $rcsfile" >&2
    exit 2
    ;;
esac

temp="$dir/$(basename "$rcsfile" ,v)"

# Redirecting ci's input from /dev/null seems to be the only way to
# avoid creating a log message.
ci -u "$original" "$rcsfile" < /dev/null

co -u -M "$rcsfile" "$temp"
mv "$temp" "$dir/$(date -r "$temp" +%Y-%m-%d).${suffix}"
keep-at-most 4 "$dir/"????-??-??".${suffix}"