new_comment_id = function(id)
	local corename = id:gsub('%.md$', '')
	-- there'll be a collision on avarage every #Random_string_chars^(n/2) = 1296 comments
	local n = 4
	local result = ('%s-%s.md'):format(corename, random_string(4))
	if file_exists(comment_path(result)) then
		-- retry
		-- This will infinite loop every #Random_string_chars^n = 1.6M, but it'll start taking a long time by halfway as long.
		return new_comment_id(id)
	end
	return result
end