What I expected to happen
While standing on a block and breaking it, a clean render of the breaking block texture to appear

What happened instead
The breaking block texture is subject to Z-fighting with the block texture, and occasionally depending on position you are standing, doesn't render at all, despite the block still breaking fine
Seems to be worse when crouching(holding L Shift) and while breaking blocks with your fist as opposed to with a tool

How to reproduce
1. Stand on top of any block
2. Try to break the block
3. Watch the Z-fighting
4. Move around slightly while still looking down at the block to see rendering stop at times

screenshots below all taken within seconds of each other, while breaking the same block

(apologies if this has been reported before, I had searched but could not find a record of an issue report of this in 1.7)