Non-full blocks showing full block hitbox through water (a.k.a. can't be waterlogged)

Non-full blocks (glass panes, iron bars, fences, slabs and more) has a normal block's "hitbox" seen through water. It is quite hard to explain, but there should be screenshots attached. 

Hope this was enough information and that the screenshots explain it better than I did.

(Never used the "Report Bug" system. Hope I did everything right)