SpongeForge: [1.12.2] Vanilla-like armor is completely ignored when player takes damage

I am currently running

• SpongeForge version: 1.12.2-2838-7.3.1-RC4093
• Forge version: 2847

Issue Description This commit - 720b576 (build RC4081) - changed some handling of how armor parameters are put into place, but didn’t alter any algorithms. As a result - all Vanilla-like armor (that extends ItemArmor) is completely ignored by all damage sources. Restoring prop = new ISpecialArmor.ArmorProperties(0, 0, Integer.MAX_VALUE); to prop = new ISpecialArmor.ArmorProperties(0, armor.damageReduceAmount / 25D, Integer.MAX_VALUE); brings armor back to how it is supposed to work.

While yes, those lines really did change in Forge the way the commit above alters them, there were also other changes to the way things are processed. The complete list of changes can be found in this commit: https://github.com/MinecraftForge/MinecraftForge/commit/e1ddc4315ca3a0ae97a337f08e1f136baa5d0930

I tried to re-implement them myself, but the ominous warning: // Beware all ye who enter here, for there's nothing but black magic here. wasn’t as ironic as I thought.

So I suggest to either revert 720b576 and leave the issues fixed by Forge PR unfixed, or to try and figure out, how to alter the rest of the code to process those changes correctly.