End Crystals that explode due to taking damage without a source entity, as well as Minecarts with TNT that explode for any reason other than being hit/damaged by a flaming arrow/trident, will not deal any damage to players or other entities (though they will still cause knockback and destroy blocks). Seemingly, any time either of these entities would normally deal explosion damage (rather than player_explosion), they instead deal nothing* (i.e. anything that would cause the “… blew up” death message, rather than the “… was blown up by …” one).

*With the exception of a destroyed End Crystal damaging the Ender Dragon it was healing (which still happens).

Steps to Reproduce:

End Crystal

1. Place, find, or summon an End Crystal.
2. Stand next to it and damage it in any way that doesn't have a “source”, for example, hitting it with a snowball/egg from a dispenser (MC-256942/MC-44280), having lightning strike nearby, etc., or just run:

   damage <end crystal> 0

   • (<end crystal> can be filled in by facing it and using tab-complete.)
3. Observe that you get pushed away, but are not damaged (as are any nearby (movable) entities).

Correct behavior:

1. Place, find, or summon an(other) End Crystal.
2. Stand next to it and damage it (non-explosively) in any way that does have a “source”, for example, simply punching it, hitting it with any arrow/trident/fireball, etc., or run:

   damage <end crystal> 0 minecraft:generic by <any entity> 
   

   • (minecraft:generic can be any damage type not in the #is_explosion tag (MC-118429).)
3. Observe that you are probably dead.

Minecart with TNT

1. Place or summon a Minecart with TNT.
2. Ignite it via an activator rail or fire/explosion damage, or have it detonate by crashing into a wall, and stand next to it as it explodes.
3. Observe (once again) that you are pushed back, but completely unscathed.

Correct behavior:

1. Get out another TNT Minecart.
2. Have it detonate by hitting it with any on-fire arrow, spectral arrow, or trident while standing next to it.
3. Observe that you take damage normally.