setCanPickupItems ignored for some mobs

[kangarko]

Paper 1.14.2 build 96
More info here: kangarko/Boss#312

Basically, the flag setCanPickupItems seems to be ignored for some mobs. Here is a description reported by one of my customers:

All of the illager bosses I have made are picking up my members items and upon death, they do not drop them. We tried to enable a gamerule so mob grief is permanently disabled, but it is only making it worse (they still pick up the weapons), not sure what's going on and I have had to give them back their items via spawning.

It happened again, but strangely enough, with a Spider and Stray Skeleton lol.

[caojohnny]

So far as I am able to tell, both mobGriefing and LivingEntity#getCanPickupItems() have to be true in order to be able to naturally pickup items in the first place, so the fact that setting the former to false making things worse doesn't really make any sense.

[kangarko]

I see, I added a listener for entity pickup along with debug messages to my plugin, we will see what the user will report. I am pretty sure he has mobGriefing enabled (?).

[zachbr]

We are aware of at least one case in which vanilla does not check it for raiders. Going to treat as a bug.

From one of the internal channels:

[kangarko]

Thanks for professional and responsive input!