1 files changed, 80 insertions, 0 deletions
diff --git a/patches/removed/1.19.2-legacy-chunksystem/0729-Prevent-unload-calls-removing-tickets-for-sync-loads.patch b/patches/removed/1.19.2-legacy-chunksystem/0729-Prevent-unload-calls-removing-tickets-for-sync-loads.patch
new file mode 100644
index 0000000000..516b5b8e0c
--- /dev/null
+++ b/patches/removed/1.19.2-legacy-chunksystem/0729-Prevent-unload-calls-removing-tickets-for-sync-loads.patch
@@ -0,0 +1,80 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <[email protected]>
+Date: Thu, 18 Jun 2020 18:23:20 -0700
+Subject: [PATCH] Prevent unload() calls removing tickets for sync loads
+
+
+diff --git a/src/main/java/net/minecraft/server/level/DistanceManager.java b/src/main/java/net/minecraft/server/level/DistanceManager.java
+index b2df5e18ce5260a9781052db7afb0b9786fb887c..537d34a0325a985948c744929b90144a66a35ee3 100644
+--- a/src/main/java/net/minecraft/server/level/DistanceManager.java
++++ b/src/main/java/net/minecraft/server/level/DistanceManager.java
+@@ -545,7 +545,7 @@ public abstract class DistanceManager {
+     }
+ 
+     public void removeTicketsOnClosing() {
+-        ImmutableSet<TicketType<?>> immutableset = ImmutableSet.of(TicketType.UNKNOWN, TicketType.POST_TELEPORT, TicketType.LIGHT, TicketType.FUTURE_AWAIT, TicketType.ASYNC_LOAD); // Paper - add additional tickets to preserve
++        ImmutableSet<TicketType<?>> immutableset = ImmutableSet.of(TicketType.UNKNOWN, TicketType.POST_TELEPORT, TicketType.LIGHT, TicketType.FUTURE_AWAIT, TicketType.ASYNC_LOAD, TicketType.REQUIRED_LOAD); // Paper - add additional tickets to preserve
+         ObjectIterator objectiterator = this.tickets.long2ObjectEntrySet().fastIterator();
+ 
+         while (objectiterator.hasNext()) {
+diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+index 29ba8971ceffbac68290f6063a69c98065e9bcba..2390fcbc1b21653b1753a58da33f936cec43d0cb 100644
+--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
++++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+@@ -537,6 +537,8 @@ public class ServerChunkCache extends ChunkSource {
+         return completablefuture;
+     }
+ 
++    private long syncLoadCounter; // Paper - prevent plugin unloads from removing our ticket
++
+     private CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>> getChunkFutureMainThread(int chunkX, int chunkZ, ChunkStatus leastStatus, boolean create) {
+         // Paper start - add isUrgent - old sig left in place for dirty nms plugins
+         return getChunkFutureMainThread(chunkX, chunkZ, leastStatus, create, false);
+@@ -555,9 +557,12 @@ public class ServerChunkCache extends ChunkSource {
+             ChunkHolder.FullChunkStatus currentChunkState = ChunkHolder.getFullChunkStatus(playerchunk.getTicketLevel());
+             currentlyUnloading = (oldChunkState.isOrAfter(ChunkHolder.FullChunkStatus.BORDER) && !currentChunkState.isOrAfter(ChunkHolder.FullChunkStatus.BORDER));
+         }
++        final Long identifier; // Paper - prevent plugin unloads from removing our ticket
+         if (create && !currentlyUnloading) {
+             // CraftBukkit end
+             this.distanceManager.addTicket(TicketType.UNKNOWN, chunkcoordintpair, l, chunkcoordintpair);
++            identifier = Long.valueOf(this.syncLoadCounter++); // Paper - prevent plugin unloads from removing our ticket
++            this.distanceManager.addTicket(TicketType.REQUIRED_LOAD, chunkcoordintpair, l, identifier); // Paper - prevent plugin unloads from removing our ticket
+             if (isUrgent) this.distanceManager.markUrgent(chunkcoordintpair); // Paper - Chunk priority
+             if (this.chunkAbsent(playerchunk, l)) {
+                 ProfilerFiller gameprofilerfiller = this.level.getProfiler();
+@@ -568,13 +573,21 @@ public class ServerChunkCache extends ChunkSource {
+                 playerchunk = this.getVisibleChunkIfPresent(k);
+                 gameprofilerfiller.pop();
+                 if (this.chunkAbsent(playerchunk, l)) {
++                    this.distanceManager.removeTicket(TicketType.REQUIRED_LOAD, chunkcoordintpair, l, identifier); // Paper
+                     throw (IllegalStateException) Util.pauseInIde(new IllegalStateException("No chunk holder after ticket has been added"));
+                 }
+             }
+-        }
+ 
++        } else { identifier = null; } // Paper - prevent plugin unloads from removing our ticket
+         // Paper start - Chunk priority
+         CompletableFuture<Either<ChunkAccess, ChunkHolder.ChunkLoadingFailure>> future = this.chunkAbsent(playerchunk, l) ? ChunkHolder.UNLOADED_CHUNK_FUTURE : playerchunk.getOrScheduleFuture(leastStatus, this.chunkMap);
++        // Paper start - prevent plugin unloads from removing our ticket
++        if (create && !currentlyUnloading) {
++            future.thenAcceptAsync((either) -> {
++                ServerChunkCache.this.distanceManager.removeTicket(TicketType.REQUIRED_LOAD, chunkcoordintpair, l, identifier);
++            }, ServerChunkCache.this.mainThreadProcessor);
++        }
++        // Paper end - prevent plugin unloads from removing our ticket
+         if (isUrgent) {
+             future.thenAccept(either -> this.distanceManager.clearUrgent(chunkcoordintpair));
+         }
+diff --git a/src/main/java/net/minecraft/server/level/TicketType.java b/src/main/java/net/minecraft/server/level/TicketType.java
+index 3c1698ba0d3bc412ab957777d9b5211dbc555208..41ddcf6775f99c56cf4b13b284420061e5dd6bdc 100644
+--- a/src/main/java/net/minecraft/server/level/TicketType.java
++++ b/src/main/java/net/minecraft/server/level/TicketType.java
+@@ -31,6 +31,7 @@ public class TicketType<T> {
+     public static final TicketType<Unit> PLUGIN = TicketType.create("plugin", (a, b) -> 0); // CraftBukkit
+     public static final TicketType<org.bukkit.plugin.Plugin> PLUGIN_TICKET = TicketType.create("plugin_ticket", (plugin1, plugin2) -> plugin1.getClass().getName().compareTo(plugin2.getClass().getName())); // CraftBukkit
+     public static final TicketType<Long> DELAY_UNLOAD = create("delay_unload", Long::compareTo, 300); // Paper
++    public static final TicketType<Long> REQUIRED_LOAD = create("required_load", Long::compareTo); // Paper - make sure getChunkAt does not fail
+ 
+     public static <T> TicketType<T> create(String name, Comparator<T> argumentComparator) {
+         return new TicketType<>(name, argumentComparator, 0L);