Remove wall-time / unused skip tick protection (#11412)

Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.

1 files changed, 19 insertions, 0 deletions

diff --git a/patches/server/0568-Prevent-AFK-kick-while-watching-end-credits.patch b/patches/server/0568-Prevent-AFK-kick-while-watching-end-credits.patch
new file mode 100644
index 0000000000..42e8c37d20
--- /dev/null
+++ b/patches/server/0568-Prevent-AFK-kick-while-watching-end-credits.patch
@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Noah van der Aa <[email protected]>
+Date: Sat, 24 Jul 2021 16:54:11 +0200
+Subject: [PATCH] Prevent AFK kick while watching end credits
+
+
+diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+index 08c4d0b79dc1c6e51105487b96e9333a5dd904d7..44d1cd3e6047590a989a2b85c759be4c64125a47 100644
+--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
++++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+@@ -397,7 +397,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
+             --this.dropSpamTickCount;
+         }
+ 
+-        if (this.player.getLastActionTime() > 0L && this.server.getPlayerIdleTimeout() > 0 && Util.getMillis() - this.player.getLastActionTime() > (long) this.server.getPlayerIdleTimeout() * 1000L * 60L) {
++        if (this.player.getLastActionTime() > 0L && this.server.getPlayerIdleTimeout() > 0 && Util.getMillis() - this.player.getLastActionTime() > (long) this.server.getPlayerIdleTimeout() * 1000L * 60L && !this.player.wonGame) { // Paper - Prevent AFK kick while watching end credits
+             this.player.resetLastActionTime(); // CraftBukkit - SPIGOT-854
+             this.disconnect((Component) Component.translatable("multiplayer.disconnect.idling"), org.bukkit.event.player.PlayerKickEvent.Cause.IDLING); // Paper - kick event cause
+         }