Half slabs allows you to go through

 I was building around with slabs and i found this bug.If you place a half slab and walk from underneath it, it actually allows you to go through. If yoy try to jump, you wont get to the top of the slab.

Step to repoduce:

•Place a half slab two block high from the ground.

•Walk through the slab without jumping.

•Then you get it

Observed outcome:

You can go through it

Expected outcome:

You will stop since it should be a wall

The process can be seen in the following screenshots