Update head rotation in missing places (#5481)

patches/server/0812-Update-head-rotation-in-missing-places.patch

@@ -0,0 +1,29 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
+Date: Mon, 21 Jun 2021 21:55:23 -0400
+Subject: [PATCH] Update head rotation in missing places
+
+In certain areas the player's head rotation could be desynced when teleported/moved.
+This is because bukkit uses a separate head rotation field for yaw.
+This issue only applies to players.
+
+diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
+index 94857a736d2a16e8ade286c6f2ddf8bd798008eb..4f164f238177b5e2b18c76b7cc14596ec93409d1 100644
+--- a/src/main/java/net/minecraft/world/entity/Entity.java
++++ b/src/main/java/net/minecraft/world/entity/Entity.java
+@@ -1742,6 +1742,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
+         this.setXRot(Mth.clamp(pitch, -90.0F, 90.0F) % 360.0F);
+         this.yRotO = this.getYRot();
+         this.xRotO = this.getXRot();
++        this.setYHeadRot(yaw); // Paper - Update head rotation
+     }
+ 
+     public void absMoveTo(double x, double y, double z) {
+@@ -1780,6 +1781,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
+         this.setXRot(pitch);
+         this.setOldPosAndRot();
+         this.reapplyPosition();
++        this.setYHeadRot(yaw); // Paper - Update head rotation
+     }
+ 
+     public final void setOldPosAndRot() {