The function `BLI_findlinkfrom` returns the link that is n-steps after the given start link. This did not work for negative steps. This change makes it so that both positive and negative step values work.
The function `BLI_findlinkfrom` returns the link that is n-steps after the given start link. This did not work for negative steps. This change makes it so that both positive and negative step values work.