1 files changed, 41 insertions, 0 deletions
diff --git a/patches/server/0768-Don-t-use-level-random-in-entity-constructors.patch b/patches/server/0768-Don-t-use-level-random-in-entity-constructors.patch
new file mode 100644
index 0000000000..b8da0480ac
--- /dev/null
+++ b/patches/server/0768-Don-t-use-level-random-in-entity-constructors.patch
@@ -0,0 +1,41 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jake Potrebic <[email protected]>
+Date: Sun, 10 Jul 2022 14:13:22 -0700
+Subject: [PATCH] Don't use level random in entity constructors
+
+Paper makes the entity random thread-safe
+and constructing an entity off the main thread
+should be supported. Some entities (for whatever
+reason) use the level's random in some places.
+
+diff --git a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+index 459f793a6603d4f98c84df4e549f069298c54985..8aaca29b115a55bf48306e71432c4c20d2bd21dc 100644
+--- a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
++++ b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+@@ -66,7 +66,12 @@ public class ItemEntity extends Entity implements TraceableEntity {
+     }
+ 
+     public ItemEntity(Level world, double x, double y, double z, ItemStack stack) {
+-        this(world, x, y, z, stack, world.random.nextDouble() * 0.2D - 0.1D, 0.2D, world.random.nextDouble() * 0.2D - 0.1D);
++        // Paper start - Don't use level random in entity constructors (to make them thread-safe)
++        this(EntityType.ITEM, world);
++        this.setPos(x, y, z);
++        this.setDeltaMovement(this.random.nextDouble() * 0.2D - 0.1D, 0.2D, this.random.nextDouble() * 0.2D - 0.1D);
++        this.setItem(stack);
++        // Paper end - Don't use level random in entity constructors
+     }
+ 
+     public ItemEntity(Level world, double x, double y, double z, ItemStack stack, double velocityX, double velocityY, double velocityZ) {
+diff --git a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
+index 3408337b11f04337bb2f62de343e430d94d3a093..cd7b955754b809826048b80723e2e9055b373a4a 100644
+--- a/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
++++ b/src/main/java/net/minecraft/world/entity/item/PrimedTnt.java
+@@ -43,7 +43,7 @@ public class PrimedTnt extends Entity implements TraceableEntity {
+     public PrimedTnt(Level world, double x, double y, double z, @Nullable LivingEntity igniter) {
+         this(EntityType.TNT, world);
+         this.setPos(x, y, z);
+-        double d3 = world.random.nextDouble() * 6.2831854820251465D;
++        double d3 = this.random.nextDouble() * 6.2831854820251465D; // Paper - Don't use level random in entity constructors
+ 
+         this.setDeltaMovement(-Math.sin(d3) * 0.02D, 0.20000000298023224D, -Math.cos(d3) * 0.02D);
+         this.setFuse(80);