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/0708-Dont-resent-entity-on-art-update.patch b/patches/server/0708-Dont-resent-entity-on-art-update.patch
new file mode 100644
index 0000000000..38d1a4ca58
--- /dev/null
+++ b/patches/server/0708-Dont-resent-entity-on-art-update.patch
@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Owen1212055 <[email protected]>
+Date: Wed, 8 Jun 2022 11:04:47 -0400
+Subject: [PATCH] Dont resent entity on art update
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPainting.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPainting.java
+index dd02cec9a82794a6b001c3b64f031f78d5fbb812..bcac1359c667ef1ee46384f9c7a5adf4010d2b08 100644
+--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPainting.java
++++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPainting.java
+@@ -36,7 +36,7 @@ public class CraftPainting extends CraftHanging implements Painting {
+             painting.setDirection(painting.getDirection());
+             return false;
+         }
+-        this.update();
++        //this.update(); Paper - Don't resent entity on art update
+         return true;
+     }
+