Unexpected behaviour when using entity:Kill() while iterating through FindInCapsule/FindInRadius

[Spearkiller]

I'm making a familiar (Which, in this situation, is technically a bomb due to complications regarding TryThrow not working on familiars, but that's besides the point but feel it worth mentioning just in case that plays a part in the issue) that when thrown, destroys any projectiles that it collides with. I have been doing this with

for k, v in pairs(Isaac.FindInCapsule(bomb:GetCollisionCapsule(), EntityPartition.BULLET)) do
        v:Kill()
end

A note that this is done in a MC_PRE_BOMB_UPDATE callback. POST_BOMB_COLLISION does not fire in this circumstance.

When testing, I found that, inexplicably, enemies would randomly die when hit by my familiar/bomb. After some further experimentation, I found that removing the v:Kill() call stopped this from happening.

Some other things I have tested/noticed:

• Sometimes, entities outside of the collision capsule would be killed instead.
• Doing print(v.Type) always printed "9" into the console (EntityType.ENTITY_PROJECTILE)
• Changing it to if v:ToProjectile() then v:Kill() end had no effect and npcs would continue to randomly die as before.
• Using FindInRadius also demonstrated strange behaviour.
• Changing it to Remove() works as expected.
• Creating a table, copying all the entities to be killed into that table, and then doing a second iteration through that, also checking if v:ToProjectile() then did not stop non-projectiles being killed.

Initially I had thought this was just an issue with FindInCapsule, but further testing has left me stumped.

[Sylmir]

Your title mentions FindInRadius in addition to FindInCapsule, but I can't seem to find any references to it in the description of the issue ? Did you do some tests with FindInRadius, or is it a typo in the title of the issue ? (I'm asking because I'm more familar with FindInRadius... Extremely questionable implementation, so what you describe would not surprise me that much if it applied to FindInRadius)

[Spearkiller]

oop, I mustve forgotten to mention it, but yes, I tested using FindInRadius as well.