Cancel own-player equipment packets in 1.9->1.8

[InstantlyMoist]

fixes players wearing a chestplate on their head, and boots as their leggings. seems to be only the case when items are applied directly into the players inventory. im not sure if this has any other side-effects.

[florianreuth]

Doesn't this always cancel the full packet now? This looks definitely wrong, maybe only the slot shifting needs an extra client player check.

[InstantlyMoist]

i'm not sure, the armor issue was fixed for me like this and still appears just fine.

[roccodev]

Judging by the comment, I'm assuming it's related to ViaVersion/ViaBackwards#1321, but if so the change should probably be done there, but I can't reproduce the issue there

[florianreuth]

Seems right, VB now sends SET_EQUIPMENT for the client player while it previously didn't, so we didn't notice the issue.

[roccodev]

Unfortunately this breaks the use case mentioned in my VB patch, I'll investigate though I still don't quite understand how to reproduce the issue here. I am using a plugin to set a player's helmet while in a GUI and it works fine for me. I've also tried setting other armor pieces and those work too.

[roccodev]

In fact you don't even need a plugin GUI for this. This PR breaks the following scenario, tested on a 26.3 server:

• Open a chest in 1.8
• From another client/console, run /item replace entity @p armor.chest with minecraft:diamond_chestplate (select the 1.8 player)
• Notice how the armor doesn't update (and without the patch, it updates fine in the chestplate slot)