PaperMC/paper-server/patches/sources/net/minecraft/commands/Commands.java.patch

--- a/net/minecraft/commands/Commands.java
+++ b/net/minecraft/commands/Commands.java
@@ -138,6 +138,14 @@
 import net.minecraft.world.flag.FeatureFlags;
 import net.minecraft.world.level.GameRules;
 import org.slf4j.Logger;
+
+// CraftBukkit start
+import com.google.common.base.Joiner;
+import java.util.Collection;
+import java.util.LinkedHashSet;
+import org.bukkit.event.player.PlayerCommandSendEvent;
+import org.bukkit.event.server.ServerCommandEvent;
+// CraftBukkit end
 
 public class Commands {
 
@@ -151,6 +159,7 @@
     private final com.mojang.brigadier.CommandDispatcher<CommandSourceStack> dispatcher = new com.mojang.brigadier.CommandDispatcher();
 
     public Commands(Commands.CommandSelection environment, CommandBuildContext commandRegistryAccess) {
+        // Paper
         AdvancementCommands.register(this.dispatcher);
         AttributeCommand.register(this.dispatcher, commandRegistryAccess);
         ExecuteCommand.register(this.dispatcher, commandRegistryAccess);
@@ -250,8 +259,33 @@
 
         if (environment.includeIntegrated) {
             PublishCommand.register(this.dispatcher);
+        }
+
+        // Paper start - Vanilla command permission fixes
+        for (final CommandNode<CommandSourceStack> node : this.dispatcher.getRoot().getChildren()) {
+            if (node.getRequirement() == com.mojang.brigadier.builder.ArgumentBuilder.<CommandSourceStack>defaultRequirement()) {
+                node.requirement = stack -> stack.source == CommandSource.NULL || stack.getBukkitSender().hasPermission(org.bukkit.craftbukkit.command.VanillaCommandWrapper.getPermission(node));
+            }
         }
+        // Paper end - Vanilla command permission fixes
+        // Paper start - Brigadier Command API
+        // Create legacy minecraft namespace commands
+        for (final CommandNode<CommandSourceStack> node : new java.util.ArrayList<>(this.dispatcher.getRoot().getChildren())) {
+            // The brigadier dispatcher is not able to resolve nested redirects.
+            // E.g. registering the alias minecraft:tp cannot redirect to tp, as tp itself redirects to teleport.
+            // Instead, target the first none redirecting node.
+            CommandNode<CommandSourceStack> flattenedAliasTarget = node;
+            while (flattenedAliasTarget.getRedirect() != null) flattenedAliasTarget = flattenedAliasTarget.getRedirect();
 
+            this.dispatcher.register(
+                com.mojang.brigadier.builder.LiteralArgumentBuilder.<CommandSourceStack>literal("minecraft:" + node.getName())
+                    .executes(flattenedAliasTarget.getCommand())
+                    .requires(flattenedAliasTarget.getRequirement())
+                    .redirect(flattenedAliasTarget)
+            );
+        }
+        // Paper end - Brigadier Command API
+        // Paper - remove public constructor, no longer needed
         this.dispatcher.setConsumer(ExecutionCommandSource.resultConsumer());
     }
 
@@ -262,30 +296,75 @@
         return new ParseResults(commandcontextbuilder1, parseResults.getReader(), parseResults.getExceptions());
     }
 
-    public void performPrefixedCommand(CommandSourceStack source, String command) {
-        command = command.startsWith("/") ? command.substring(1) : command;
-        this.performCommand(this.dispatcher.parse(command, source), command);
+    // CraftBukkit start
+    public void dispatchServerCommand(CommandSourceStack sender, String command) {
+        Joiner joiner = Joiner.on(" ");
+        if (command.startsWith("/")) {
+            command = command.substring(1);
+        }
+
+        ServerCommandEvent event = new ServerCommandEvent(sender.getBukkitSender(), command);
+        org.bukkit.Bukkit.getPluginManager().callEvent(event);
+        if (event.isCancelled()) {
+            return;
+        }
+        command = event.getCommand();
+
+        String[] args = command.split(" ");
+        if (args.length == 0) return; // Paper - empty commands shall not be dispatched
+
+        // Paper - Fix permission levels for command blocks
+
+        // Handle vanilla commands;
+        if (sender.getLevel().getCraftServer().getCommandBlockOverride(args[0])) {
+            args[0] = "minecraft:" + args[0];
+        }
+
+        String newCommand = joiner.join(args);
+        this.performPrefixedCommand(sender, newCommand, newCommand);
+    }
+    // CraftBukkit end
+
+    public void performPrefixedCommand(CommandSourceStack source, String command) {
+        // CraftBukkit start
+        this.performPrefixedCommand(source, command, command);
     }
 
+    public void performPrefixedCommand(CommandSourceStack commandlistenerwrapper, String s, String label) {
+        s = s.startsWith("/") ? s.substring(1) : s;
+        this.performCommand(this.dispatcher.parse(s, commandlistenerwrapper), s, label);
+        // CraftBukkit end
+    }
+
     public void performCommand(ParseResults<CommandSourceStack> parseResults, String command) {
-        CommandSourceStack commandlistenerwrapper = (CommandSourceStack) parseResults.getContext().getSource();
+        this.performCommand(parseResults, command, command);
+    }
 
+    public void performCommand(ParseResults<CommandSourceStack> parseresults, String s, String label) { // CraftBukkit
+        // Paper start
+        this.performCommand(parseresults, s, label, false);
+    }
+    public void performCommand(ParseResults<CommandSourceStack> parseresults, String s, String label, boolean throwCommandError) {
+        // Paper end
+        CommandSourceStack commandlistenerwrapper = (CommandSourceStack) parseresults.getContext().getSource();
+
         Profiler.get().push(() -> {
-            return "/" + command;
+            return "/" + s;
         });
-        ContextChain<CommandSourceStack> contextchain = Commands.finishParsing(parseResults, command, commandlistenerwrapper);
+        ContextChain contextchain = this.finishParsing(parseresults, s, commandlistenerwrapper, label); // CraftBukkit // Paper - Add UnknownCommandEvent
 
         try {
             if (contextchain != null) {
                 Commands.executeCommandInContext(commandlistenerwrapper, (executioncontext) -> {
-                    ExecutionContext.queueInitialCommandExecution(executioncontext, command, contextchain, commandlistenerwrapper, CommandResultCallback.EMPTY);
+                    ExecutionContext.queueInitialCommandExecution(executioncontext, s, contextchain, commandlistenerwrapper, CommandResultCallback.EMPTY);
                 });
             }
         } catch (Exception exception) {
+            if (throwCommandError) throw exception;
             MutableComponent ichatmutablecomponent = Component.literal(exception.getMessage() == null ? exception.getClass().getName() : exception.getMessage());
 
-            if (Commands.LOGGER.isDebugEnabled()) {
-                Commands.LOGGER.error("Command exception: /{}", command, exception);
+            Commands.LOGGER.error("Command exception: /{}", s, exception); // Paper - always show execution exception in console log
+            if (commandlistenerwrapper.getServer().isDebugging() || Commands.LOGGER.isDebugEnabled()) { // Paper - Debugging
                 StackTraceElement[] astacktraceelement = exception.getStackTrace();
 
                 for (int i = 0; i < Math.min(astacktraceelement.length, 3); ++i) {
@@ -298,7 +377,7 @@
             }));
             if (SharedConstants.IS_RUNNING_IN_IDE) {
                 commandlistenerwrapper.sendFailure(Component.literal(Util.describeError(exception)));
-                Commands.LOGGER.error("'/{}' threw an exception", command, exception);
+                Commands.LOGGER.error("'/{}' threw an exception", s, exception);
             }
         } finally {
             Profiler.get().pop();
@@ -307,18 +386,22 @@
     }
 
     @Nullable
-    private static ContextChain<CommandSourceStack> finishParsing(ParseResults<CommandSourceStack> parseResults, String command, CommandSourceStack source) {
+    private ContextChain<CommandSourceStack> finishParsing(ParseResults<CommandSourceStack> parseresults, String s, CommandSourceStack commandlistenerwrapper, String label) { // CraftBukkit // Paper - Add UnknownCommandEvent
         try {
-            Commands.validateParseResults(parseResults);
-            return (ContextChain) ContextChain.tryFlatten(parseResults.getContext().build(command)).orElseThrow(() -> {
-                return CommandSyntaxException.BUILT_IN_EXCEPTIONS.dispatcherUnknownCommand().createWithContext(parseResults.getReader());
+            Commands.validateParseResults(parseresults);
+            return (ContextChain) ContextChain.tryFlatten(parseresults.getContext().build(s)).orElseThrow(() -> {
+                return CommandSyntaxException.BUILT_IN_EXCEPTIONS.dispatcherUnknownCommand().createWithContext(parseresults.getReader());
             });
         } catch (CommandSyntaxException commandsyntaxexception) {
-            source.sendFailure(ComponentUtils.fromMessage(commandsyntaxexception.getRawMessage()));
+            // Paper start - Add UnknownCommandEvent
+            final net.kyori.adventure.text.TextComponent.Builder builder = net.kyori.adventure.text.Component.text();
+            // commandlistenerwrapper.sendFailure(ComponentUtils.fromMessage(commandsyntaxexception.getRawMessage()));
+            builder.color(net.kyori.adventure.text.format.NamedTextColor.RED).append(io.papermc.paper.brigadier.PaperBrigadier.componentFromMessage(commandsyntaxexception.getRawMessage()));
+            // Paper end - Add UnknownCommandEvent
             if (commandsyntaxexception.getInput() != null && commandsyntaxexception.getCursor() >= 0) {
                 int i = Math.min(commandsyntaxexception.getInput().length(), commandsyntaxexception.getCursor());
                 MutableComponent ichatmutablecomponent = Component.empty().withStyle(ChatFormatting.GRAY).withStyle((chatmodifier) -> {
-                    return chatmodifier.withClickEvent(new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, "/" + command));
+                    return chatmodifier.withClickEvent(new ClickEvent(ClickEvent.Action.SUGGEST_COMMAND, "/" + label)); // CraftBukkit // Paper
                 });
 
                 if (i > 10) {
@@ -333,8 +416,18 @@
                 }
 
                 ichatmutablecomponent.append((Component) Component.translatable("command.context.here").withStyle(ChatFormatting.RED, ChatFormatting.ITALIC));
-                source.sendFailure(ichatmutablecomponent);
+                // Paper start - Add UnknownCommandEvent
+                // commandlistenerwrapper.sendFailure(ichatmutablecomponent);
+                builder
+                    .append(net.kyori.adventure.text.Component.newline())
+                    .append(io.papermc.paper.adventure.PaperAdventure.asAdventure(ichatmutablecomponent));
             }
+            org.bukkit.event.command.UnknownCommandEvent event = new org.bukkit.event.command.UnknownCommandEvent(commandlistenerwrapper.getBukkitSender(), s, org.spigotmc.SpigotConfig.unknownCommandMessage.isEmpty() ? null : builder.build());
+            org.bukkit.Bukkit.getServer().getPluginManager().callEvent(event);
+            if (event.message() != null) {
+                commandlistenerwrapper.sendFailure(io.papermc.paper.adventure.PaperAdventure.asVanilla(event.message()), false);
+                // Paper end - Add UnknownCommandEvent
+            }
 
             return null;
         }
@@ -368,7 +461,7 @@
 
                 executioncontext1.close();
             } finally {
-                Commands.CURRENT_EXECUTION_CONTEXT.set((Object) null);
+                Commands.CURRENT_EXECUTION_CONTEXT.set(null); // CraftBukkit - decompile error
             }
         } else {
             callback.accept(executioncontext);
@@ -377,23 +470,121 @@
     }
 
     public void sendCommands(ServerPlayer player) {
-        Map<CommandNode<CommandSourceStack>, CommandNode<SharedSuggestionProvider>> map = Maps.newHashMap();
+        // Paper start - Send empty commands if tab completion is disabled
+        if (org.spigotmc.SpigotConfig.tabComplete < 0) {
+            player.connection.send(new ClientboundCommandsPacket(new RootCommandNode<>()));
+            return;
+        }
+        // Paper end - Send empty commands if tab completion is disabled
+        // CraftBukkit start
+        // Register Vanilla commands into builtRoot as before
+        // Paper start - Perf: Async command map building
+        // Copy root children to avoid concurrent modification during building
+        final Collection<CommandNode<CommandSourceStack>> commandNodes = new java.util.ArrayList<>(this.dispatcher.getRoot().getChildren());
+        COMMAND_SENDING_POOL.execute(() -> this.sendAsync(player, commandNodes));
+    }
+
+    // Fixed pool, but with discard policy
+    public static final java.util.concurrent.ExecutorService COMMAND_SENDING_POOL = new java.util.concurrent.ThreadPoolExecutor(
+        2, 2, 0, java.util.concurrent.TimeUnit.MILLISECONDS,
+        new java.util.concurrent.LinkedBlockingQueue<>(),
+        new com.google.common.util.concurrent.ThreadFactoryBuilder()
+            .setNameFormat("Paper Async Command Builder Thread Pool - %1$d")
+            .setUncaughtExceptionHandler(new net.minecraft.DefaultUncaughtExceptionHandlerWithName(net.minecraft.server.MinecraftServer.LOGGER))
+            .build(),
+        new java.util.concurrent.ThreadPoolExecutor.DiscardPolicy()
+    );
+
+    private void sendAsync(ServerPlayer player, Collection<CommandNode<CommandSourceStack>> dispatcherRootChildren) {
+        // Paper end - Perf: Async command map building
+        Map<CommandNode<CommandSourceStack>, CommandNode<SharedSuggestionProvider>> map = Maps.newIdentityHashMap(); // Use identity to prevent aliasing issues
+        // Paper - brigadier API removes the need to fill the map twice
         RootCommandNode<SharedSuggestionProvider> rootcommandnode = new RootCommandNode();
 
         map.put(this.dispatcher.getRoot(), rootcommandnode);
-        this.fillUsableCommands(this.dispatcher.getRoot(), rootcommandnode, player.createCommandSourceStack(), map);
+        this.fillUsableCommands(dispatcherRootChildren, rootcommandnode, player.createCommandSourceStack(), map); // Paper - Perf: Async command map building; pass copy of children
+
+        Collection<String> bukkit = new LinkedHashSet<>();
+        for (CommandNode node : rootcommandnode.getChildren()) {
+            bukkit.add(node.getName());
+        }
+        // Paper start - Perf: Async command map building
+        new com.destroystokyo.paper.event.brigadier.AsyncPlayerSendCommandsEvent<CommandSourceStack>(player.getBukkitEntity(), (RootCommandNode) rootcommandnode, false).callEvent(); // Paper - Brigadier API
+        net.minecraft.server.MinecraftServer.getServer().execute(() -> {
+           runSync(player, bukkit, rootcommandnode);
+        });
+    }
+
+    private void runSync(ServerPlayer player, Collection<String> bukkit, RootCommandNode<SharedSuggestionProvider> rootcommandnode) {
+        // Paper end - Perf: Async command map building
+        new com.destroystokyo.paper.event.brigadier.AsyncPlayerSendCommandsEvent<CommandSourceStack>(player.getBukkitEntity(), (RootCommandNode) rootcommandnode, true).callEvent(); // Paper - Brigadier API
+        PlayerCommandSendEvent event = new PlayerCommandSendEvent(player.getBukkitEntity(), new LinkedHashSet<>(bukkit));
+        event.getPlayer().getServer().getPluginManager().callEvent(event);
+
+        // Remove labels that were removed during the event
+        for (String orig : bukkit) {
+            if (!event.getCommands().contains(orig)) {
+                rootcommandnode.removeCommand(orig);
+            }
+        }
+        // CraftBukkit end
         player.connection.send(new ClientboundCommandsPacket(rootcommandnode));
     }
 
-    private void fillUsableCommands(CommandNode<CommandSourceStack> tree, CommandNode<SharedSuggestionProvider> result, CommandSourceStack source, Map<CommandNode<CommandSourceStack>, CommandNode<SharedSuggestionProvider>> resultNodes) {
-        Iterator iterator = tree.getChildren().iterator();
+    // Paper start - Perf: Async command map building; pass copy of children
+    private void fillUsableCommands(Collection<CommandNode<CommandSourceStack>> children, CommandNode<SharedSuggestionProvider> result, CommandSourceStack source, Map<CommandNode<CommandSourceStack>, CommandNode<SharedSuggestionProvider>> resultNodes) {
+        resultNodes.keySet().removeIf((node) -> !org.spigotmc.SpigotConfig.sendNamespaced && node.getName().contains( ":" )); // Paper - Remove namedspaced from result nodes to prevent redirect trimming ~ see comment below
+        Iterator iterator = children.iterator();
+        // Paper end - Perf: Async command map building
 
         while (iterator.hasNext()) {
             CommandNode<CommandSourceStack> commandnode2 = (CommandNode) iterator.next();
+            // Paper start - Brigadier API
+            if (commandnode2.clientNode != null) {
+                commandnode2 = commandnode2.clientNode;
+            }
+            // Paper end - Brigadier API
+            if ( !org.spigotmc.SpigotConfig.sendNamespaced && commandnode2.getName().contains( ":" ) ) continue; // Spigot
 
             if (commandnode2.canUse(source)) {
-                ArgumentBuilder<SharedSuggestionProvider, ?> argumentbuilder = commandnode2.createBuilder();
+                ArgumentBuilder argumentbuilder = commandnode2.createBuilder(); // CraftBukkit - decompile error
+                // Paper start
+                /*
+                Because of how commands can be yeeted right left and center due to bad bukkit practices
+                we need to be able to ensure that ALL commands are registered (even redirects).
 
+                What this will do is IF the redirect seems to be "dead" it will create a builder and essentially populate (flatten)
+                all the children from the dead redirect to the node.
+
+                So, if minecraft:msg redirects to msg but the original msg node has been overriden minecraft:msg will now act as msg and will explicilty inherit its children.
+
+                The only way to fix this is to either:
+                - Send EVERYTHING flattened, don't use redirects
+                - Don't allow command nodes to be deleted
+                - Do this :)
+                 */
+
+                // Is there an invalid command redirect?
+                if (argumentbuilder.getRedirect() != null && (CommandNode) resultNodes.get(argumentbuilder.getRedirect()) == null) {
+                    // Create the argument builder with the same values as the specified node, but with a different literal and populated children
+
+                    CommandNode<CommandSourceStack> redirect = argumentbuilder.getRedirect();
+                    // Diff copied from LiteralCommand#createBuilder
+                    final com.mojang.brigadier.builder.LiteralArgumentBuilder<CommandSourceStack> builder = com.mojang.brigadier.builder.LiteralArgumentBuilder.literal(commandnode2.getName());
+                    builder.requires(redirect.getRequirement());
+                    // builder.forward(redirect.getRedirect(), redirect.getRedirectModifier(), redirect.isFork()); We don't want to migrate the forward, since it's invalid.
+                    if (redirect.getCommand() != null) {
+                        builder.executes(redirect.getCommand());
+                    }
+                    // Diff copied from LiteralCommand#createBuilder
+                    for (CommandNode<CommandSourceStack> child : redirect.getChildren()) {
+                        builder.then(child);
+                    }
+
+                    argumentbuilder = builder;
+                }
+                // Paper end
+
                 argumentbuilder.requires((icompletionprovider) -> {
                     return true;
                 });
@@ -415,12 +606,12 @@
                     argumentbuilder.redirect((CommandNode) resultNodes.get(argumentbuilder.getRedirect()));
                 }
 
-                CommandNode<SharedSuggestionProvider> commandnode3 = argumentbuilder.build();
+                CommandNode commandnode3 = argumentbuilder.build(); // CraftBukkit - decompile error
 
                 resultNodes.put(commandnode2, commandnode3);
                 result.addChild(commandnode3);
                 if (!commandnode2.getChildren().isEmpty()) {
-                    this.fillUsableCommands(commandnode2, commandnode3, source, resultNodes);
+                    this.fillUsableCommands(commandnode2.getChildren(), commandnode3, source, resultNodes); // Paper - Perf: Async command map building; pass children directly
                 }
             }
         }
@@ -481,7 +672,7 @@
             }
 
             private <T> HolderLookup.RegistryLookup.Delegate<T> createLookup(final HolderLookup.RegistryLookup<T> original) {
-                return new HolderLookup.RegistryLookup.Delegate<T>(this) {
+                return new HolderLookup.RegistryLookup.Delegate<T>() { // CraftBukkit - decompile error
                     @Override
                     public HolderLookup.RegistryLookup<T> parent() {
                         return original;