Players don't receive thorns damage when attacking entities wearing thorns armor with indirect sweeping attacks

The Bug:

Players don't receive thorns damage when attacking entities wearing thorns armor with indirect sweeping attacks.

Steps to Reproduce:

1. Place down a command block and input the command provided below into it.

   /summon minecraft:zombie ~ ~1 ~ {ArmorItems:[{id:"minecraft:diamond_boots",tag:{Enchantments:[{id:"minecraft:thorns",lvl:3}]},Count:1b},{id:"minecraft:diamond_leggings",tag:{Enchantments:[{id:"minecraft:thorns",lvl:3}]},Count:1b},{id:"minecraft:diamond_chestplate",tag:{Enchantments:[{id:"minecraft:thorns",lvl:3}]},Count:1b},{id:"minecraft:diamond_helmet",tag:{Enchantments:[{id:"minecraft:thorns",lvl:3}]},Count:1b}]}

2. Activate the command block, obtain a wooden sword, and summon another zombie by using the command provided below.

   /summon minecraft:zombie ~ ~ ~ {ArmorItems:[{},{},{},{id:"minecraft:iron_helmet",Count:1b}]}

3. Switch to survival mode and wait for both of the zombies to begin approaching you.
4. Using a sweeping attacking, attack the zombie with the iron helmet so that the zombie with the thorns armor is also damaged as well.
5. Do this multiple times and observe if you receive thorns damage.
6. Take note as to whether or not players receive thorns damage when attacking entities wearing thorns armor with indirect sweeping attacks.

Observed Behavior:

Players don't receive thorns damage.

Expected Behavior:

Players would receive thorns damage.