The bug

Dying from a Ghast's fireball can cause your items to be deleted instead of dropping.
Note that deaths caused by summoned fireballs do not delete your items.

To reproduce:

1. Create a Superflat world.

2. Stay still on the ground and run these commands:

   /fill ~-2 ~-1 ~-2 ~3 ~4 ~7 bedrock hollow
   /fill ~-2 ~4 ~-2 ~3 ~4 ~2 air
   /fill ~2 ~ ~2 ~-1 ~ ~2 bedrock
   /fill ~-1 ~ ~-1 ~2 ~ ~1 water
   /summon minecraft:ghast ~0.5 ~ ~4.5
   /spawnpoint @s ~ ~5 ~3 -180

3. Pick up any block.

4. Switch to Survival mode.

5. Let the Ghast kill you.
   (x) Verify whether your items disappear instead of dropping.

What I expected to happen was:

When killed by a Ghast's fireball, my items would drop.

What actually happened was:

My items were deleted.