Explosions combine block drops and drop them at the wrong location

The bug

Explosions now combine block drops and then drop them randomly at the position of any destroyed block, possibly not even the same block type.

How to reproduce

1. /fill ~1 ~ ~1 ~5 ~ ~5 orange_wool
   

2. /fill ~2 ~ ~2 ~4 ~ ~4 cyan_wool
   

3. /summon tnt ~3 ~1 ~3
   

Demonstrational video

https://youtu.be/pTMX3hX7mZE