Fix crash when a keybinding with a category not known to MC gets added

src/main/java/org/dimdev/rift/listener/client/LocalCommandAdder.java

@@ -0,0 +1,8 @@
+package org.dimdev.rift.listener.client;
+
+import com.mojang.brigadier.CommandDispatcher;
+import net.minecraft.command.CommandSource;
+
+public interface LocalCommandAdder {
+    void registerLocalCommands(CommandDispatcher<CommandSource> dispatcher);
+}

src/main/java/org/dimdev/rift/mixin/hook/client/MixinGuiChat.java

@@ -0,0 +1,54 @@
+package org.dimdev.rift.mixin.hook.client;
+
+import com.mojang.brigadier.suggestion.Suggestion;
+import net.minecraft.client.gui.GuiChat;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import com.mojang.brigadier.suggestion.Suggestions;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import net.minecraft.client.gui.GuiTextField;
+import org.dimdev.rift.util.LocalCommandManager;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(GuiChat.class)
+public class MixinGuiChat {
+
+    @Shadow GuiTextField inputField;
+
+    @Redirect(method="showSuggestions",
+            at=@At(value="INVOKE",
+                   target="Ljava/util/concurrent/CompletableFuture;join()Ljava/lang/Object;",
+                   remap=false)
+            )
+
+    // We need to declare this to return Object, not Suggestions, because the
+    // redirected method is type polymorphic and thus returns Object,
+    // not Suggestions, in its byte code definition.
+
+    public Object gotServerSideSuggestions(CompletableFuture<Suggestions> pendingSuggestions) {
+        Suggestions server=pendingSuggestions.join();
+        Suggestions local=LocalCommandManager.getSuggestions(inputField.getText());
+
+        if (local==null || local.isEmpty()) {
+            return server;
+        }
+
+        if (server.isEmpty()) {
+            return local;
+        }
+
+        if (!local.getRange().equals(server.getRange())) {
+            System.err.println("something wrong with ranges");
+            return server;
+        }
+
+        List<Suggestion> results=new ArrayList<>();
+        results.addAll(server.getList());
+        results.addAll(local.getList());
+        Suggestions result=new Suggestions(server.getRange(), results);
+        return result;
+    }
+}

src/main/java/org/dimdev/rift/mixin/hook/client/MixinKeyBinding.java

@@ -0,0 +1,21 @@
+package org.dimdev.rift.mixin.hook.client;
+
+import java.util.Map;
+import net.minecraft.client.settings.KeyBinding;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(KeyBinding.class)
+public class MixinKeyBinding {
+    @Shadow private static Map<String, Integer> CATEGORY_ORDER;
+    @Inject(method = "<init>", at = @At("RETURN"))
+    private void insertCategory(String description,
+            int keycode, String category, CallbackInfo ci) {
+        if (CATEGORY_ORDER.get(category)==null) {
+            CATEGORY_ORDER.put(category, CATEGORY_ORDER.size());
+        }
+    }
+}

src/main/java/org/dimdev/rift/mixin/hook/client/MixinLocalCommand.java

@@ -0,0 +1,25 @@
+package org.dimdev.rift.mixin.hook.client;
+
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import net.minecraft.client.entity.EntityPlayerSP;
+import org.dimdev.rift.util.LocalCommandManager;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(EntityPlayerSP.class)
+public class MixinLocalCommand {
+    @Inject(method="sendChatMessage", at=@At("HEAD"), cancellable=true)
+    private void handleLocalCommand(String message, CallbackInfo callbackInfo) {
+        if (message.startsWith("/")) {
+            try {
+                LocalCommandManager.dispatchLocalCommand(message.substring(1));
+                callbackInfo.cancel();
+            } catch (CommandSyntaxException ex) {
+                // Don't do anything, it wasn't intended to be our command.
+                // Not cancelling callbackInfo will make MC send the command to the server.
+            }
+        }
+    }
+}

src/main/java/org/dimdev/rift/util/LocalCommandManager.java

@@ -0,0 +1,67 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package org.dimdev.rift.util;
+
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.ParseResults;
+import com.mojang.brigadier.StringReader;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import com.mojang.brigadier.suggestion.Suggestions;
+import java.util.concurrent.CompletableFuture;
+import net.minecraft.command.CommandSource;
+import org.dimdev.rift.listener.client.LocalCommandAdder;
+import org.dimdev.riftloader.RiftLoader;
+
+/**
+ *
+ * @author gbl
+ */
+public class LocalCommandManager {
+
+    private static LocalCommandManager instance;
+    private CommandDispatcher<CommandSource> dispatcher;
+    private CompletableFuture<Suggestions> suggestions;
+
+    private LocalCommandManager() {
+    }
+
+    public static LocalCommandManager getInstance() {
+        if (instance == null) {
+            instance=new LocalCommandManager();
+            instance.dispatcher=new CommandDispatcher<>();
+
+            for (LocalCommandAdder localCommandAdder: RiftLoader.instance.getListeners(LocalCommandAdder.class)) {
+                localCommandAdder.registerLocalCommands(instance.dispatcher);
+            }
+        }
+        return instance;
+    }
+
+    public static void dispatchLocalCommand(String s) throws CommandSyntaxException {
+        getInstance().dispatcher.execute(s, null);
+    }
+
+    private Suggestions getSuggestionsFor(String command) {
+        if (!command.startsWith("/")) {
+		    return null;
+        }
+        // Don't just pass command; pass a stringreader that skips over the '/',
+        // or Suggestions.range won't match the server version.
+        StringReader reader=new StringReader(command);
+        reader.skip();
+        ParseResults<CommandSource> parse = dispatcher.parse(reader, null);
+        // We are losing the advantage of using a separate thread here,
+        // but the server commands, which imply a network exchange,
+        // need it much more than we do.
+        suggestions = dispatcher.getCompletionSuggestions(parse);
+        Suggestions result = suggestions.join();
+        return result;
+    }
+
+    public static Suggestions getSuggestions(String s) {
+        return getInstance().getSuggestionsFor(s);
+    }
+}

src/main/resources/mixins.rift.hooks.json

@@ -41,13 +41,16 @@
     "MixinItemTool"
   ],
   "client": [
+    "client.MixinGuiChat",
+    "client.MixinLocalCommand",
     "client.MixinMinecraft",
     "client.MixinModelBakery",
     "client.MixinNetHandlerPlayClient",
     "client.MixinTileEntityRendererDispatcher",
     "client.MixinRenderManager",
     "client.MixinEntityPlayerSP",
     "client.MixinGameSettings",
-    "client.MixinGuiIngame"
+    "client.MixinGuiIngame",
+    "client.MixinKeyBinding"
   ]
 }