__find_redo_targets()
{
	local IFS=$'\n:'
	for d in . ../.. $PATH; do
		if [ -x "$d/redo-targets" ]; then
			( cd "$d" && echo "$PWD/redo-targets" )
			break
		fi
	done
}
__redo_targets=$(__find_redo_targets)


__redo_completions()
{
	local cur="${COMP_WORDS[COMP_CWORD]}"
	local IFS=$'\n'
	local targets=$(
		# targets already known to redo
		[ -x "$__redo_targets" ] &&
		"$__redo_targets" |
		while read name; do
			rest=${name#$cur}
			[ "$cur$rest" != "$name" ] && continue
			name2="$cur${rest%%/*}"
			[ -d "$name2/." ] || echo "$name2"
		done
		
		# targets named explicitly by .do files
		compgen -o default "$cur" |
		while read name; do
			local don=${name%.do} def=${name#default.}
			[ "$don" = "$name" -o "$def" != "$name" ] && continue
			echo "${name%.do}"
		done
	)
	COMPREPLY=($(compgen -W "$targets" "$cur"))
}

complete -F __redo_completions -o plusdirs -o filenames redo do