lattejed/a-star-lua — pull request #1 by superquadratic (2013-07-05 10:35:57+00:00)
Title: Make sure f_score is a consecutive list at all times

Since `f_score` is iterated over using `ipairs()`, it must always be a consecutive list. Therefore, `remove_node()` must not leave a hole when removing an item from the list.