Two-by-two arrangements of jungle or spruce saplings cannot grow when there are adjacent blocks located north or west of the sapling formation

The Bug:

Two-by-two arrangements of jungle or spruce saplings cannot grow when surrounded by any block other than a sapling that's located to the north and/or west side of the sapling formation.

This can be anything from a torch to a snow layer, to a grass block. The south and east sides do not have this blocking effect.

Steps to Reproduce:

1. Build the setup as shown in the attachment below. setup.png
2. Apply large amounts of bone meal to the said saplings.
3. Take note as to whether or not two-by-two arrangements of jungle or spruce saplings cannot grow when there are adjacent blocks located north or west of the sapling formation.

Observed Behavior:

The saplings will never grow into trees naturally or when bone mealed.

Expected Behavior:

The saplings would grow into trees and not be prevented by adjacent blocks located north or west of the sapling formation.