That's intentional game design.
I've gotten inside my walls.
I did a quick search but didn't find anything after 1.4
@PotholedSea40 No they shouldn't
There are too many so a lower spawn rate would be fine but I don't think zombified piglins should spawn there.
Seems to happen in my zombie grinder only when they are pushed up against another block but I have not tested that.
THIS IS IN 1.12!!!
Items which do not use block textures as the texture when dropped render infront of chests and possibly more entities(E.g. blocks like bedrock, stone and oak planks render properly. Items like sticks armor and tools do not. Glass is an exception to this.) Ghast fireballs render infront of ghasts even though the fireball is behind.