Bone Meal will not grow saplings enclosed in a 3x3 area

When a sapling (for example, spruce) is enclosed in a 3x3 area, bone meal will not grow the sapling into a tree. This means that many automatic tree farm designs are broken. This worked in pre-release 2 but has been broken since then. When looking at the changelog for pre-release 3, it doesn't seem to address anything with saplings.