Upstream has released updates that appears 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:
bb813f6f SPIGOT-4605: Warn against hacking physics
CraftBukkit Changes:
2ced0233 Don't handle sync packets for kicked players
d5e96882 SPIGOT-4602: Cache reflection in decompile error workaround
Spigot Changes:
b0f4c22b SPIGOT-4605: Catch more physics problems