From def8b96d4bcf0df8ffb1e40ea9be4090fe9c775b Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sat, 11 Jul 2020 03:54:28 -0400
Subject: [PATCH] Thread Safe Vanilla Command permission checking

Datapacks check this on load and are built concurrently. This was breaking them badly due
to race conditions.

Plus, .canUse we want to be safe for async anyways.
---
 .../com/mojang/brigadier/tree/CommandNode.java.patch |  4 ++--
 .../minecraft/commands/CommandSourceStack.java.patch | 12 +++++++-----
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/paper-server/patches/sources/com/mojang/brigadier/tree/CommandNode.java.patch b/paper-server/patches/sources/com/mojang/brigadier/tree/CommandNode.java.patch
index e574812b9..a38dc4015 100644
--- a/paper-server/patches/sources/com/mojang/brigadier/tree/CommandNode.java.patch
+++ b/paper-server/patches/sources/com/mojang/brigadier/tree/CommandNode.java.patch
@@ -40,10 +40,10 @@
 +    public synchronized boolean canUse(final S source) {
 +        if (source instanceof CommandSourceStack) {
 +            try {
-+                ((CommandSourceStack) source).currentCommand = this;
++                ((CommandSourceStack) source).currentCommand.put(Thread.currentThread(), this); // Paper - Thread Safe Vanilla Command permission checking
 +                return this.requirement.test(source);
 +            } finally {
-+                ((CommandSourceStack) source).currentCommand = null;
++                ((CommandSourceStack) source).currentCommand.remove(Thread.currentThread()); // Paper - Thread Safe Vanilla Command permission checking
 +            }
 +        }
 +        // CraftBukkit end
diff --git a/paper-server/patches/sources/net/minecraft/commands/CommandSourceStack.java.patch b/paper-server/patches/sources/net/minecraft/commands/CommandSourceStack.java.patch
index 0d80d5087..766f7556b 100644
--- a/paper-server/patches/sources/net/minecraft/commands/CommandSourceStack.java.patch
+++ b/paper-server/patches/sources/net/minecraft/commands/CommandSourceStack.java.patch
@@ -15,12 +15,12 @@
      private final Vec2 rotation;
      private final CommandSigningContext signingContext;
      private final TaskChainer chatMessageChainer;
-+    public volatile CommandNode currentCommand; // CraftBukkit
++    public java.util.Map<Thread, CommandNode> currentCommand = new java.util.concurrent.ConcurrentHashMap<>(); // CraftBukkit // Paper - Thread Safe Vanilla Command permission checking
 +    public boolean bypassSelectorPermissions = false; // Paper - add bypass for selector permissions
  
      public CommandSourceStack(CommandSource output, Vec3 pos, Vec2 rot, ServerLevel world, int level, String name, Component displayName, MinecraftServer server, @Nullable Entity entity) {
          this(output, pos, rot, world, level, name, displayName, server, entity, false, CommandResultCallback.EMPTY, EntityAnchorArgument.Anchor.FEET, CommandSigningContext.ANONYMOUS, TaskChainer.immediate(server));
-@@ -169,11 +172,45 @@
+@@ -169,11 +172,47 @@
          return this.textName;
      }
  
@@ -47,9 +47,11 @@
 +    @Override
      public boolean hasPermission(int level) {
 +        // CraftBukkit start
-+        CommandNode currentCommand = this.currentCommand;
++        // Paper start - Thread Safe Vanilla Command permission checking
++        CommandNode currentCommand = this.currentCommand.get(Thread.currentThread());
 +        if (currentCommand != null) {
 +            return this.hasPermission(level, org.bukkit.craftbukkit.command.VanillaCommandWrapper.getPermission(currentCommand));
++            // Paper end - Thread Safe Vanilla Command permission checking
 +        }
 +        // CraftBukkit end
 +
@@ -66,7 +68,7 @@
      public Vec3 getPosition() {
          return this.worldPosition;
      }
-@@ -302,21 +339,26 @@
+@@ -302,21 +341,26 @@
              while (iterator.hasNext()) {
                  ServerPlayer entityplayer = (ServerPlayer) iterator.next();
  
@@ -96,7 +98,7 @@
          }
  
      }
-@@ -400,4 +442,10 @@
+@@ -400,4 +444,10 @@
      public boolean isSilent() {
          return this.silent;
      }