Expected Behavior

Lithium should not change any block hitboxes.

Actual Behavior

Lithium has fewer hitboxes than vanilla, e.g. inside extended piston bases or daylight sensors.

Reproduction Steps

Build this contraption (using soul sand, and setblock the piston then)
In Vanilla the outcome is a) while in Lithium the outcome is b).

Analysis

It is caused by Lithium replacing the cuboid method that creates VoxelShapes. In vanilla sometimes VoxelShapes with a BitSet are created. They have a collision box at every bit border (8th or 4th of a block) that is inside the cuboid. Lithium does not have those collision boxes inside the cuboid.
Disabling shapes.specialized_shapes works around the issue.

Attachments

a) https://cdn.discordapp.com/attachments/648967810139029505/724030415480029284/2020-06-21_00.38.00.png
b) https://cdn.discordapp.com/attachments/648967810139029505/724030982176374956/2020-06-21_00.40.32.png

Fixed in 0abafdf