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Restore safe End portal falling-block duplication #307

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Merged
R00tB33rMan merged 12 commits into from
Aug 12, 2026
Merged

Restore safe End portal falling-block duplication #307

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4964bcc
Safely continue falling block ticks after End portal transfers
BaconCat1 Jul 29, 2026
5f86363
Merge branch 'CraftCanvasMC:main' into fix/sand-duplication
BaconCat1 Jul 29, 2026
3c3f4f2
Cleanup diff
BaconCat1 Jul 30, 2026
d9d2ffa
Move changes to region threading base patch
BaconCat1 Jul 30, 2026
dc1b82f
Merge branch 'CraftCanvasMC:main' into fix/sand-duplication
BaconCat1 Jul 30, 2026
76eafd0
Polish portal continuation patch
BaconCat1 Jul 30, 2026
913e217
Remove Region Threading patch artifact
BaconCat1 Jul 30, 2026
355b20a
Merge branch 'CraftCanvasMC:main' into fix/sand-duplication
BaconCat1 Aug 1, 2026
ec25e40
Fix Nitpicks
BaconCat1 Aug 1, 2026
75978ee
Address Review Feedback
BaconCat1 Aug 3, 2026
de9a025
Fix Nitpick
BaconCat1 Aug 11, 2026
ffdabb0
Resolve conflicts with master/main / whatever dueris renamed it to
BaconCat1 Aug 12, 2026
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210 changes: 195 additions & 15 deletions canvas-server/minecraft-patches/base/0004-Region-Threading.patch
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Original file line number Diff line number Diff line change
Expand Up @@ -24121,7 +24121,7 @@ index bb5f66c62c9541bb76a9faad9e9ee91c1466fc6a..66d7bb9418832638c220a08d06c01ef0
return blockToFallLocation(blockState);
} else {
diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227590fea87 100644
index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..472b82ad0416786766c0ffb43007e5eac11de673 100644
--- a/net/minecraft/world/entity/Entity.java
+++ b/net/minecraft/world/entity/Entity.java
@@ -170,7 +170,7 @@ public abstract class Entity
Expand Down Expand Up @@ -24397,7 +24397,28 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
}

public int getDimensionChangingDelay() {
@@ -4038,7 +4108,1138 @@ public abstract class Entity
@@ -4021,12 +4091,20 @@ public abstract class Entity
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}

public void restoreFrom(final Entity oldEntity) {
+ // Canvas start - copy entity data without forwarding the Bukkit handle
+ this.restoreFrom(oldEntity, true);
+ }
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+
+ public void restoreFrom(final Entity oldEntity, final boolean forwardBukkitEntity) {
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+ // Canvas end - copy entity data without forwarding the Bukkit handle
// Paper start - Forward CraftEntity in teleport command
+ if (forwardBukkitEntity) { // Canvas - copy entity data without forwarding the Bukkit handle
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org.bukkit.craftbukkit.entity.CraftEntity bukkitEntity = oldEntity.bukkitEntity;
if (bukkitEntity != null) {
bukkitEntity.setHandle(this);
this.bukkitEntity = bukkitEntity;
}
+ } // Canvas - copy entity data without forwarding the Bukkit handle
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// Paper end - Forward CraftEntity in teleport command
try (ProblemReporter.ScopedCollector reporter = new ProblemReporter.ScopedCollector(this.problemPath(), LOGGER)) {
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TagValueOutput entityData = TagValueOutput.createWithContext(reporter, oldEntity.registryAccess());
@@ -4038,7 +4116,1162 @@ public abstract class Entity
this.portalProcess = oldEntity.portalProcess;
}

Expand Down Expand Up @@ -25308,6 +25329,16 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
+
+ }
+
+ // Canvas start - safely continue falling block ticks after starting an End portal transfer
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+ protected @Nullable Runnable canvas$preparePortalTransferContinuation(
+ final ServerLevel origin,
+ final ServerLevel destination,
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+ final PortalType type
+ ) {
+ return null;
+ }
+ // Canvas end - safely continue falling block ticks after starting an End portal transfer
+
+ // note: destination param is mutable because we mutate this
+ // later in event handling
+ // note: teleportComplete param is nullable
Expand Down Expand Up @@ -25347,6 +25378,10 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
+ canvas$ensureCanPortalAsync(destination, takePassengers);
+ }
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+ final ServerLevel finalDestination = destination;
+
+ // set the portal transfer continuation for falling block ticks for portal transfers
+ final java.lang.Runnable portalTransferContinuation =
+ this.canvas$preparePortalTransferContinuation(originWorld, finalDestination, type);
+ // Canvas end - region threading
+
+ Vec3 initialPosition = this.position();
Expand Down Expand Up @@ -25381,6 +25416,16 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
+ // Canvas end - region threading
+ }
+
+ // Canvas start - safely continue falling block ticks after starting an End portal transfer
+ if (portalTransferContinuation != null) {
+ try {
+ portalTransferContinuation.run();
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+ } catch (final Throwable thrown) {
+ LOGGER.error("Failed to run a source-side portal transfer continuation", thrown);
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+ }
+ }
+
+ // Canvas end - safely continue falling block ticks after starting an End portal transfer
+ // ensure the region is always ticking in case of a shutdown
+ // otherwise, the shutdown will not be able to complete the shutdown as it requires a ticking region
+ Long teleportHoldId = Long.valueOf(TELEPORT_HOLD_TICKET_GEN.getAndIncrement());
Expand Down Expand Up @@ -25536,7 +25581,7 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
// Paper start - Fix item duplication and teleport issues
if ((!this.isAlive() || !this.valid) && (transition.newLevel() != this.level)) {
LOGGER.warn("Illegal Entity Teleport {} to {}:{}", this, transition.newLevel(), transition.position(), new Throwable());
@@ -4240,6 +5441,12 @@ public abstract class Entity
@@ -4240,6 +5473,12 @@ public abstract class Entity
}
}

Expand All @@ -25549,7 +25594,7 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
protected void removeAfterChangingDimensions() {
this.setRemoved(Entity.RemovalReason.CHANGED_DIMENSION, null); // CraftBukkit - add Bukkit remove cause
if (this instanceof Leashable leashable && leashable.isLeashed()) { // Paper - only call if it is leashed
@@ -4573,6 +5780,12 @@ public abstract class Entity
@@ -4573,6 +5812,12 @@ public abstract class Entity
}

public void startSeenByPlayer(final ServerPlayer player) {
Expand All @@ -25562,7 +25607,7 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
}

public void stopSeenByPlayer(final ServerPlayer player) {
@@ -4582,6 +5795,12 @@ public abstract class Entity
@@ -4582,6 +5827,12 @@ public abstract class Entity
new io.papermc.paper.event.player.PlayerUntrackEntityEvent(player.getBukkitEntity(), this.getBukkitEntity()).callEvent();
}
// Paper end - entity tracking events
Expand All @@ -25575,7 +25620,7 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
}

public float rotate(final Rotation rotation) {
@@ -4989,7 +6208,10 @@ public abstract class Entity
@@ -4989,7 +6240,10 @@ public abstract class Entity
return;
}
// Paper end - Block invalid positions and bounding box
Expand All @@ -25587,7 +25632,7 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
this.position = new Vec3(x, y, z);
int fx = Mth.floor(x);
int fy = Mth.floor(y);
@@ -5020,7 +6242,7 @@ public abstract class Entity
@@ -5020,7 +6274,7 @@ public abstract class Entity
}
// Paper start - Block invalid positions and bounding box; don't allow desync of pos and AABB
// hanging has its own special logic
Expand All @@ -25596,23 +25641,23 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
this.setBoundingBox(this.makeBoundingBox());
}
// Paper end - Block invalid positions and bounding box
@@ -5095,6 +6317,7 @@ public abstract class Entity
@@ -5095,6 +6349,7 @@ public abstract class Entity
Util.logAndPauseIfInIde("Invalid entity rotation: " + yRot + ", discarding.");
} else {
this.yRot = yRot;
+ this.canvas$threadSafeYRot = yRot; // Canvas - region threading
}
}

@@ -5107,6 +6330,7 @@ public abstract class Entity
@@ -5107,6 +6362,7 @@ public abstract class Entity
Util.logAndPauseIfInIde("Invalid entity rotation: " + xRot + ", discarding.");
} else {
this.xRot = Math.clamp(xRot % 360.0F, -90.0F, 90.0F);
+ this.canvas$threadSafeXRot = this.xRot; // Canvas - region threading
}
}

@@ -5126,6 +6350,12 @@ public abstract class Entity
@@ -5126,6 +6382,12 @@ public abstract class Entity
return this.removalReason != null;
}

Expand All @@ -25625,15 +25670,15 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
public Entity.@Nullable RemovalReason getRemovalReason() {
return this.removalReason;
}
@@ -5140,6 +6370,7 @@ public abstract class Entity
@@ -5140,6 +6402,7 @@ public abstract class Entity
// Paper end - rewrite chunk system
org.bukkit.craftbukkit.event.CraftEventFactory.callEntityRemoveEvent(this, cause); // CraftBukkit
final boolean alreadyRemoved = this.removalReason != null; // Paper - Folia schedulers
+ this.preRemove(removalReason); // Folia - region threading
if (this.removalReason == null) {
this.removalReason = reason;
}
@@ -5163,6 +6394,10 @@ public abstract class Entity
@@ -5163,6 +6426,10 @@ public abstract class Entity
this.removalReason = null;
}

Expand All @@ -25644,7 +25689,7 @@ index bd935ae0cafc8fa2f53ed756a9acedab9db54b30..e87539cdd9813e68fe105d5311221227
// Paper start - Folia schedulers
/**
* Invoked only when the entity is truly removed from the server, never to be added to any world.
@@ -5174,7 +6409,7 @@ public abstract class Entity
@@ -5174,7 +6441,7 @@ public abstract class Entity
// Paper end - Folia schedulers
// Paper start - optimise Folia entity scheduler
public final void registerScheduler() {
Expand Down Expand Up @@ -26771,10 +26816,32 @@ index 4d0d58d5cbfa88fdd0f5ea3b9d96b21a88f2f988..154e4de3262ee9f56c121eb42cb54495
}
}
diff --git a/net/minecraft/world/entity/item/FallingBlockEntity.java b/net/minecraft/world/entity/item/FallingBlockEntity.java
index 899f4ac76ae1397146bf15c4e5b9f5996451c2b5..0917beab5437f6a7a64b0f1f327dbfbaf6cb76a8 100644
index 899f4ac76ae1397146bf15c4e5b9f5996451c2b5..e9c6016fe2eed7f8f72c0a88aefe8ac2295c22e7 100644
--- a/net/minecraft/world/entity/item/FallingBlockEntity.java
+++ b/net/minecraft/world/entity/item/FallingBlockEntity.java
@@ -165,7 +165,7 @@ public class FallingBlockEntity extends Entity {
@@ -71,6 +71,7 @@ public class FallingBlockEntity extends Entity {
public float fallDamagePerDistance = 0.0F;
public @Nullable CompoundTag blockData;
public boolean forceTickAfterTeleportToDuplicate;
+ private boolean canvas$finishTickOnly; // Canvas - safely continue falling block ticks after End portal transfers
protected static final EntityDataAccessor<BlockPos> DATA_START_POS = SynchedEntityData.defineId(FallingBlockEntity.class, EntityDataSerializers.BLOCK_POS);
public boolean autoExpire = true; // Paper - Expand FallingBlock API

@@ -152,20 +153,11 @@ public class FallingBlockEntity extends Entity {
this.discard(org.bukkit.event.entity.EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
} else {
Block block = this.blockState.getBlock();
- this.time++;
- this.applyGravity();
- this.move(MoverType.SELF, this.getDeltaMovement());
- this.applyEffectsFromBlocks();
- // Paper start - Configurable falling blocks height nerf
- if (this.level().paperConfig().fixes.fallingBlockHeightNerf.test(v -> this.getY() > v)) {
- if (this.dropItem && this.level() instanceof final ServerLevel serverLevel && serverLevel.getGameRules().get(GameRules.ENTITY_DROPS)) {
- this.spawnAtLocation(serverLevel, block);
- }
- this.discard(org.bukkit.event.entity.EntityRemoveEvent.Cause.OUT_OF_WORLD);
+ if (this.canvas$runFallingBlockTickPrefix(block)) { // Canvas - safely continue falling block ticks after End portal transfers
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return;
}
// Paper end - Configurable falling blocks height nerf
Expand All @@ -26783,6 +26850,119 @@ index 899f4ac76ae1397146bf15c4e5b9f5996451c2b5..0917beab5437f6a7a64b0f1f327dbfba
if (this.level() instanceof ServerLevel serverLevel && (this.isAlive() || this.forceTickAfterTeleportToDuplicate)) {
BlockPos pos = this.blockPosition();
boolean isConcrete = this.blockState.getBlock() instanceof ConcretePowderBlock;
@@ -265,6 +257,112 @@ public class FallingBlockEntity extends Entity {
}
}

+ // Canvas start - handle End portal transfer before falling block tick tail
+ private boolean canvas$runFallingBlockTickPrefix(final net.minecraft.world.level.block.Block block) {
+ if (this.canvas$finishTickOnly) {
+ this.canvas$finishTickOnly = false;
+ return false;
+ }
+
+ this.time++;
+ this.applyGravity();
+ this.move(net.minecraft.world.entity.MoverType.SELF, this.getDeltaMovement());
+ this.applyEffectsFromBlocks();
+ // Paper start - Configurable falling blocks height nerf
+ if (this.level().paperConfig().fixes.fallingBlockHeightNerf.test(value -> this.getY() > value)) {
+ if (
+ this.dropItem
+ && this.level() instanceof final net.minecraft.server.level.ServerLevel serverLevel
+ && serverLevel.getGameRules().get(net.minecraft.world.level.gamerules.GameRules.ENTITY_DROPS)
+ ) {
+ this.spawnAtLocation(serverLevel, block);
+ }
+ this.discard(org.bukkit.event.entity.EntityRemoveEvent.Cause.OUT_OF_WORLD);
+ return true;
+ }
+ // Paper end - Configurable falling blocks height nerf
+ if (
+ io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.allowUnsafeEndPortalTeleportation
+ && this.portalProcess != null
+ && this.portalProcess.isSamePortal((net.minecraft.world.level.block.Portal) net.minecraft.world.level.block.Blocks.END_PORTAL)
+ && this.handlePortal()
+ ) {
+ return true;
+ }
+
+ return false;
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+ }
+
+ @Override
+ protected @Nullable Runnable canvas$preparePortalTransferContinuation(
+ final ServerLevel origin,
+ final ServerLevel destination,
+ final Entity.PortalType type
+ ) {
+ final boolean fromOrToEnd =
+ (
+ origin.dimension() == net.minecraft.world.level.Level.END
+ || destination.dimension() == net.minecraft.world.level.Level.END
+ ) && origin.dimension() != destination.dimension();
+ if (
+ type != net.minecraft.world.entity.Entity.PortalType.END
+ || !fromOrToEnd
+ || !io.papermc.paper.configuration.GlobalConfiguration.get()
+ .unsupportedSettings
+ .allowUnsafeEndPortalTeleportation
+ ) {
+ return null;
+ }
+
+ final net.minecraft.world.entity.Entity created = this.getType()
+ .create(origin, net.minecraft.world.entity.EntitySpawnReason.DIMENSION_TRAVEL);
+ if (!(created instanceof net.minecraft.world.entity.item.FallingBlockEntity continuation)) {
+ LOGGER.error("Unable to create a falling block continuation for End portal duplication");
+ return null;
+ }
+
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+ continuation.restoreFrom(this, false);
+ continuation.setUUID(java.util.UUID.randomUUID());
+ continuation.portalProcess = null;
+ continuation.forceTickAfterTeleportToDuplicate = false;
+ continuation.setStartPos(this.getStartPos());
+ continuation.setDeltaMovement(this.getDeltaMovement());
+ continuation.xo = this.xo;
+ continuation.yo = this.yo;
+ continuation.zo = this.zo;
+ continuation.xOld = this.xOld;
+ continuation.yOld = this.yOld;
+ continuation.zOld = this.zOld;
+ continuation.yRotO = this.yRotO;
+ continuation.xRotO = this.xRotO;
+ continuation.onGround = this.onGround;
+ continuation.horizontalCollision = this.horizontalCollision;
+ continuation.verticalCollision = this.verticalCollision;
+ continuation.verticalCollisionBelow = this.verticalCollisionBelow;
+ continuation.minorHorizontalCollision = this.minorHorizontalCollision;
+
+ return () -> {
+ origin.addDuringTeleport(continuation);
+ if (continuation.hasNullCallback() || continuation.isRemoved()) {
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+ LOGGER.error(
+ "Unable to add a falling block continuation for End portal duplication because it {}",
+ continuation.hasNullCallback() ? "has a null callback" : "was removed"
+ );
+ return;
+ }
+
+ try {
+ continuation.canvas$finishTickOnly = true;
+ continuation.tick();
+ } finally {
+ if (!continuation.isRemoved()) {
+ continuation.discard();
+ }
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+ }
+ };
+ }
+
+ // Canvas end - safely continue falling block ticks after End portal transfers
public void callOnBrokenAfterFall(final Block block, final BlockPos pos) {
if (block instanceof Fallable fallable) {
fallable.onBrokenAfterFall(this.level(), pos, this);
diff --git a/net/minecraft/world/entity/item/ItemEntity.java b/net/minecraft/world/entity/item/ItemEntity.java
index c800c894a921ae77ed1757794ddf8d737b05681e..76467ded9c4eaf368cd256d53761d87bcb489864 100644
--- a/net/minecraft/world/entity/item/ItemEntity.java
Expand Down