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.

patches/server/0724-Send-block-entities-after-destroy-prediction.patch

@@ -0,0 +1,91 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
+Date: Sat, 25 Jun 2022 19:45:20 -0400
+Subject: [PATCH] Send block entities after destroy prediction
+
+Minecraft's prediction system does not handle block entities, so if we are manually sending block entities during
+block breaking we need to set it after the prediction is finished. This fixes block entities not showing when cancelling the BlockBreakEvent.
+
+diff --git a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+index 4d024956156aefde7df308642dfd0a40779e0633..6abecaac8407b992d208a9108e11fd4954a4106f 100644
+--- a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
++++ b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+@@ -63,6 +63,8 @@ public class ServerPlayerGameMode {
+     private BlockPos delayedDestroyPos;
+     private int delayedTickStart;
+     private int lastSentState;
++    public boolean captureSentBlockEntities = false; // Paper - Send block entities after destroy prediction
++    public boolean capturedBlockEntity = false; // Paper - Send block entities after destroy prediction
+ 
+     public ServerPlayerGameMode(ServerPlayer player) {
+         this.gameModeForPlayer = GameType.DEFAULT_MODE;
+@@ -193,10 +195,7 @@ public class ServerPlayerGameMode {
+                     this.player.connection.send(new ClientboundBlockUpdatePacket(pos, this.level.getBlockState(pos)));
+                     this.debugLogging(pos, false, sequence, "may not interact");
+                     // Update any tile entity data for this block
+-                    BlockEntity tileentity = this.level.getBlockEntity(pos);
+-                    if (tileentity != null) {
+-                        this.player.connection.send(tileentity.getUpdatePacket());
+-                    }
++                    capturedBlockEntity = true; // Paper - Send block entities after destroy prediction
+                     // CraftBukkit end
+                     return;
+                 }
+@@ -207,10 +206,7 @@ public class ServerPlayerGameMode {
+                     // Let the client know the block still exists
+                     this.player.connection.send(new ClientboundBlockUpdatePacket(this.level, pos));
+                     // Update any tile entity data for this block
+-                    BlockEntity tileentity = this.level.getBlockEntity(pos);
+-                    if (tileentity != null) {
+-                        this.player.connection.send(tileentity.getUpdatePacket());
+-                    }
++                    capturedBlockEntity = true; // Paper - Send block entities after destroy prediction
+                     return;
+                 }
+                 // CraftBukkit end
+@@ -395,10 +391,12 @@ public class ServerPlayerGameMode {
+                 }
+ 
+                 // Update any tile entity data for this block
++                if (!captureSentBlockEntities) { // Paper - Send block entities after destroy prediction
+                 BlockEntity tileentity = this.level.getBlockEntity(pos);
+                 if (tileentity != null) {
+                     this.player.connection.send(tileentity.getUpdatePacket());
+                 }
++                } else {capturedBlockEntity = true;} // Paper - Send block entities after destroy prediction
+                 return false;
+             }
+         }
+diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+index f05297a2b349734b9700a0e977ee9b2bba030d65..ca32e5aa6e77ca1bab886e7b6a778ec931ac4e4c 100644
+--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
++++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+@@ -1711,8 +1711,28 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
+                     return;
+                 }
+                 // Paper end - Don't allow digging into unloaded chunks
++                // Paper start - Send block entities after destroy prediction
++                this.player.gameMode.capturedBlockEntity = false;
++                this.player.gameMode.captureSentBlockEntities = true;
++                // Paper end - Send block entities after destroy prediction
+                 this.player.gameMode.handleBlockBreakAction(blockposition, packetplayinblockdig_enumplayerdigtype, packet.getDirection(), this.player.level().getMaxBuildHeight(), packet.getSequence());
+                 this.player.connection.ackBlockChangesUpTo(packet.getSequence());
++                // Paper start - Send block entities after destroy prediction
++                this.player.gameMode.captureSentBlockEntities = false;
++                // If a block entity was modified speedup the block change ack to avoid the block entity
++                // being overriden.
++                if (this.player.gameMode.capturedBlockEntity) {
++                    // manually tick
++                    this.send(new ClientboundBlockChangedAckPacket(this.ackBlockChangesUpTo));
++                    this.player.connection.ackBlockChangesUpTo = -1;
++
++                    this.player.gameMode.capturedBlockEntity = false;
++                    BlockEntity tileentity = this.player.level().getBlockEntity(blockposition);
++                    if (tileentity != null) {
++                        this.player.connection.send(tileentity.getUpdatePacket());
++                    }
++                }
++                // Paper end - Send block entities after destroy prediction
+                 return;
+             default:
+                 throw new IllegalArgumentException("Invalid player action");