Paper/Spigot-Server-Patches/0420-Fix-items-not-falling-correctly.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: AJMFactsheets <AJMFactsheets@gmail.com>
Date: Fri, 17 Jan 2020 17:17:54 -0600
Subject: [PATCH] Fix items not falling correctly

Since 1.14, Mojang has added an optimization which skips checking if
an item should fall every fourth tick.

However, Spigot's entity activation range class also has an
optimization which skips ticking active entities every fourth tick.
This can result in a state where an item will never properly fall
due to its move method never being called.

This patch resolves the conflict by offsetting checking an item's
move method from Spigot's entity activation range check.

diff --git a/src/main/java/net/minecraft/server/EntityItem.java b/src/main/java/net/minecraft/server/EntityItem.java
index 507627a29f67c380314d2fa8ee56807ced8ee56a..2926fbb95705f4389ca599c3bf0421267b83d401 100644
--- a/src/main/java/net/minecraft/server/EntityItem.java
+++ b/src/main/java/net/minecraft/server/EntityItem.java
@@ -86,7 +86,7 @@ public class EntityItem extends Entity {
                 }
             }
 
-            if (!this.onGround || b(this.getMot()) > 9.999999747378752E-6D || (this.ticksLived + this.getId()) % 4 == 0) {
+            if (!this.onGround || b(this.getMot()) > 9.999999747378752E-6D || this.ticksLived % 4 == 3) { // Paper - Ensure checking item movement is always offset from Spigot's entity activation range check
                 this.move(EnumMoveType.SELF, this.getMot());
                 float f = 0.98F;