I was in a roofed forest biome. I found a giant mushroom
I tried to select giant mushroom block(any color) to see what happens.
What happened was that every block became black. Items were still ok. They were even black in the creative inventory.
Steps to Reproduce:
1. Find or grow a giant mushroom.
2. Select a block of mushroom. Everything should become black
Duplicate of MC-35881. Basically, update your video drivers or turn mip-maps off.