Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
Bukkit Changes:
2b4b6d14 PR-1023: Convert InventoryView to interface
CraftBukkit Changes:
68603b1c1 Use expanded interaction ranges for traced interact events
eae9f760c PR-1414: Convert InventoryView to interface
ee9eafe67 Fix Implementation for DamageSource#isIndirect for internal custom causing entity
A long standing bug in spigot and its derivatives was the fact that
players taking damage while blocking with a shield would not receive
invulnerability, while they do in vanilla.
This enabled the pvp technique of disabling a shield and immediately
attacking again to knock a player into the air.
While upstream fixed this and properly aligned itself with vanilla
damage logic (in this specific case) changing such long standing
behaviour has some downsides.
To allow players used to this specific bug to still use it, this patch
introduces a configuration option to re-introduce said bug.
As there is no easy way to *only* re-add this bug, the option is found
in the unsupported section as it may introduce other damage related
disparity from vanilla.