Allow login packets to only generate on server based connections

Run injectSnapshot on the client thread, wait for result and
disconnect when injectSnapshot fails.
Fix DevServer to load MOD_CLASSES
Fix LaunchTesting to properly load log4j2 markers (don't use a
static variable in that class!)

Signed-off-by: cpw <cpw+github@weeksfamily.ca>

src/main/java/net/minecraftforge/fml/config/ConfigTracker.java

@@ -79,7 +79,7 @@ public class ConfigTracker {
         this.configSets.get(type).forEach(config -> openConfig(config, configBasePath));
     }
 
-    public List<Pair<String, FMLHandshakeMessages.S2CConfigData>> syncConfigs() {
+    public List<Pair<String, FMLHandshakeMessages.S2CConfigData>> syncConfigs(boolean isLocal) {
         final Map<String, byte[]> configData = configSets.get(ModConfig.Type.SERVER).stream().collect(Collectors.toMap(ModConfig::getFileName, mc -> { //TODO: Test cpw's LambdaExceptionUtils on Oracle javac.
             try {
                 return Files.readAllBytes(mc.getFullPath());

src/main/java/net/minecraftforge/fml/network/ConnectionType.java

@@ -30,6 +30,7 @@ public enum ConnectionType
     ConnectionType(Function<String, Integer> versionExtractor) {
         this.versionExtractor = versionExtractor;
     }
+
     public static ConnectionType forVersionFlag(String vers)
     {
         return vers.startsWith(FMLNetworkConstants.FMLNETMARKER) ? MODDED : VANILLA;

src/main/java/net/minecraftforge/fml/network/FMLHandshakeHandler.java

@@ -19,14 +19,17 @@
 
 package net.minecraftforge.fml.network;
 
+import com.google.common.collect.Multimap;
 import net.minecraft.network.NetworkManager;
 import net.minecraft.network.PacketBuffer;
 import net.minecraft.network.NetHandlerLoginServer;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.text.TextComponentString;
 import net.minecraftforge.fml.config.ConfigTracker;
+import net.minecraftforge.fml.loading.AdvancedLogMessageAdapter;
 import net.minecraftforge.fml.network.simple.SimpleChannel;
 import net.minecraftforge.registries.ForgeRegistry;
+import net.minecraftforge.registries.GameData;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.Marker;
@@ -40,6 +43,8 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 
 import static net.minecraftforge.registries.ForgeRegistry.REGISTRIES;
@@ -114,11 +119,14 @@ public class FMLHandshakeHandler {
     {
         this.direction = side;
         this.manager = networkManager;
-        if (NetworkHooks.getConnectionType(()->this.manager)==ConnectionType.VANILLA) {
+        if (networkManager.isLocalChannel()) {
+            this.messageList = NetworkRegistry.gatherLoginPayloads(this.direction, true);
+            LOGGER.debug(FMLHSMARKER, "Starting local connection.");
+        } else if (NetworkHooks.getConnectionType(()->this.manager)==ConnectionType.VANILLA) {
             this.messageList = Collections.emptyList();
             LOGGER.debug(FMLHSMARKER, "Starting new vanilla network connection.");
         } else {
-            this.messageList = NetworkRegistry.gatherLoginPayloads(this.direction);
+            this.messageList = NetworkRegistry.gatherLoginPayloads(this.direction, false);
             LOGGER.debug(FMLHSMARKER, "Starting new modded network connection. Found {} messages to dispatch.", this.messageList.size());
         }
     }
@@ -170,13 +178,48 @@ public class FMLHandshakeHandler {
         LOGGER.debug(FMLHSMARKER,"Received registry packet for {}", registryPacket.getRegistryName());
         this.registriesToReceive.remove(registryPacket.getRegistryName());
         this.registrySnapshots.put(registryPacket.getRegistryName(), registryPacket.getSnapshot());
-        contextSupplier.get().setPacketHandled(true);
-        FMLNetworkConstants.handshakeChannel.reply(new FMLHandshakeMessages.C2SAcknowledge(), contextSupplier.get());
 
+        boolean continueHandshake = true;
         if (this.registriesToReceive.isEmpty()) {
-          //TODO: @cpw injectSnapshot Needs to be on the world thread. And maybe block the network/login so we don't get world data before we finish?
-          registrySnapshots = null;
+            continueHandshake = handleRegistryLoading(contextSupplier);
         }
+        // The handshake reply isn't sent until we have processed the message
+        contextSupplier.get().setPacketHandled(true);
+        if (!continueHandshake) {
+            LOGGER.error(FMLHSMARKER, "Connection closed, not continuing handshake");
+        } else {
+            FMLNetworkConstants.handshakeChannel.reply(new FMLHandshakeMessages.C2SAcknowledge(), contextSupplier.get());
+        }
+    }
+
+    private boolean handleRegistryLoading(final Supplier<NetworkEvent.Context> contextSupplier) {
+        // We use a countdown latch to suspend the network thread pending the client thread processing the registry data
+        AtomicBoolean successfulConnection = new AtomicBoolean(false);
+        CountDownLatch block = new CountDownLatch(1);
+        contextSupplier.get().enqueueWork(() -> {
+            LOGGER.debug(FMLHSMARKER, "Injecting registry snapshot from server.");
+            final Multimap<ResourceLocation, ResourceLocation> missingData = GameData.injectSnapshot(registrySnapshots, false, false);
+            LOGGER.debug(FMLHSMARKER, "Snapshot injected.");
+            if (!missingData.isEmpty()) {
+                LOGGER.error(FMLHSMARKER, "Missing registry data for network connection:\n{}", new AdvancedLogMessageAdapter(sb->
+                        missingData.forEach((reg, entry)-> sb.append("\t").append(reg).append(": ").append(entry).append('\n'))));
+            }
+            successfulConnection.set(missingData.isEmpty());
+            block.countDown();
+        });
+        LOGGER.debug(FMLHSMARKER, "Waiting for registries to load.");
+        try {
+            block.await();
+        } catch (InterruptedException e) {
+            Thread.interrupted();
+        }
+        if (successfulConnection.get()) {
+            LOGGER.debug(FMLHSMARKER, "Registry load complete, continuing handshake.");
+        } else {
+            LOGGER.error(FMLHSMARKER, "Failed to load registry, closing connection.");
+            this.manager.closeChannel(new TextComponentString("Failed to synchronize registry data from server, closing connection"));
+        }
+        return successfulConnection.get();
     }
 
     void handleClientAck(final FMLHandshakeMessages.C2SAcknowledge msg, final Supplier<NetworkEvent.Context> contextSupplier) {

src/main/java/net/minecraftforge/fml/network/NetworkEvent.java

@@ -101,14 +101,20 @@ public class NetworkEvent extends Event
 
     public static class GatherLoginPayloadsEvent extends Event {
         private final List<NetworkRegistry.LoginPayload> collected;
+        private final boolean isLocal;
 
-        public GatherLoginPayloadsEvent(final List<NetworkRegistry.LoginPayload> loginPayloadList) {
+        public GatherLoginPayloadsEvent(final List<NetworkRegistry.LoginPayload> loginPayloadList, boolean isLocal) {
             this.collected = loginPayloadList;
+            this.isLocal = isLocal;
         }
 
         public void add(PacketBuffer buffer, ResourceLocation channelName, String context) {
             collected.add(new NetworkRegistry.LoginPayload(buffer, channelName, context));
         }
+
+        public boolean isLocal() {
+            return isLocal;
+        }
     }
 
     public static class LoginPayloadEvent extends NetworkEvent {

src/main/java/net/minecraftforge/fml/network/NetworkInstance.java

@@ -96,8 +96,8 @@ public class NetworkInstance
         return this.serverAcceptedVersions.test(clientVersion);
     }
 
-    void dispatchGatherLogin(final List<NetworkRegistry.LoginPayload> loginPayloadList) {
-        this.networkEventBus.post(new NetworkEvent.GatherLoginPayloadsEvent(loginPayloadList));
+    void dispatchGatherLogin(final List<NetworkRegistry.LoginPayload> loginPayloadList, boolean isLocal) {
+        this.networkEventBus.post(new NetworkEvent.GatherLoginPayloadsEvent(loginPayloadList, isLocal));
     }
 
     void dispatchLoginPacket(final NetworkEvent.LoginPayloadEvent loginPayloadEvent) {

src/main/java/net/minecraftforge/fml/network/NetworkRegistry.java

@@ -218,10 +218,10 @@ public class NetworkRegistry
      * @return The {@link LoginPayload} list
      * @param direction the network direction for the request - only gathers for LOGIN_TO_CLIENT
      */
-    static List<LoginPayload> gatherLoginPayloads(final NetworkDirection direction) {
+    static List<LoginPayload> gatherLoginPayloads(final NetworkDirection direction, boolean isLocal) {
         if (direction!=NetworkDirection.LOGIN_TO_CLIENT) return Collections.emptyList();
         List<LoginPayload> gatheredPayloads = new ArrayList<>();
-        instances.values().forEach(ni->ni.dispatchGatherLogin(gatheredPayloads));
+        instances.values().forEach(ni->ni.dispatchGatherLogin(gatheredPayloads, isLocal));
         return gatheredPayloads;
     }
 

src/main/java/net/minecraftforge/fml/network/simple/SimpleChannel.java

@@ -39,7 +39,7 @@ public class SimpleChannel
 {
     private final NetworkInstance instance;
     private final IndexedMessageCodec indexedCodec;
-    private List<Supplier<? extends List<? extends Pair<String,?>>>> loginPackets;
+    private List<Function<Boolean, ? extends List<? extends Pair<String,?>>>> loginPackets;
 
     public SimpleChannel(NetworkInstance instance)
     {
@@ -52,7 +52,7 @@ public class SimpleChannel
 
     private void networkLoginGather(final NetworkEvent.GatherLoginPayloadsEvent gatherEvent) {
         loginPackets.forEach(packetGenerator->{
-            packetGenerator.get().forEach(p->{
+            packetGenerator.apply(gatherEvent.isLocal()).forEach(p->{
                 PacketBuffer pb = new PacketBuffer(Unpooled.buffer());
                 this.indexedCodec.build(p.getRight(), pb);
                 gatherEvent.add(pb, this.instance.getChannelName(), p.getLeft());
@@ -125,7 +125,7 @@ public class SimpleChannel
         private BiConsumer<MSG, Supplier<NetworkEvent.Context>> consumer;
         private Function<MSG, Integer> loginIndexGetter;
         private BiConsumer<MSG, Integer> loginIndexSetter;
-        private Supplier<List<Pair<String,MSG>>> loginPacketGenerators;
+        private Function<Boolean, List<Pair<String, MSG>>> loginPacketGenerators;
 
         private static <MSG> MessageBuilder<MSG> forType(final SimpleChannel channel, final Class<MSG> type, int id) {
             MessageBuilder<MSG> builder = new MessageBuilder<>();
@@ -151,18 +151,18 @@ public class SimpleChannel
             return this;
         }
 
-        public MessageBuilder<MSG> buildLoginPacketList(Supplier<List<Pair<String,MSG>>> loginPacketGenerators) {
+        public MessageBuilder<MSG> buildLoginPacketList(Function<Boolean, List<Pair<String,MSG>>> loginPacketGenerators) {
             this.loginPacketGenerators = loginPacketGenerators;
             return this;
         }
 
         public MessageBuilder<MSG> markAsLoginPacket()
         {
-            this.loginPacketGenerators = () -> {
+            this.loginPacketGenerators = (isLocal) -> {
                 try {
                     return Collections.singletonList(Pair.of(type.getName(), type.newInstance()));
                 } catch (InstantiationException | IllegalAccessException e) {
-                    throw new RuntimeException("Inaccessible no-arg constructor for message "+type.getName(),e);
+                    throw new RuntimeException("Inaccessible no-arg constructor for message "+type.getName(), e);
                 }
             };
             return this;

src/main/java/net/minecraftforge/registries/RegistryManager.java

@@ -19,6 +19,8 @@
 
 package net.minecraftforge.registries;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -146,15 +148,15 @@ public class RegistryManager
         this.superTypes.clear();
     }
 
-    public static List<Pair<String, FMLHandshakeMessages.S2CRegistry>> generateRegistryPackets()
+    public static List<Pair<String, FMLHandshakeMessages.S2CRegistry>> generateRegistryPackets(boolean isLocal)
     {
-        return ACTIVE.takeSnapshot(false).entrySet().stream().
+        return !isLocal ? ACTIVE.takeSnapshot(false).entrySet().stream().
                 map(e->Pair.of("Registry " + e.getKey(), new FMLHandshakeMessages.S2CRegistry(e.getKey(), e.getValue()))).
-                collect(Collectors.toList());
+                collect(Collectors.toList()) : Collections.emptyList();
     }
 
     public static List<ResourceLocation> registryNames()
     {
-        return ACTIVE.registries.entrySet().stream().map(Map.Entry::getKey).collect(Collectors.toList());
+        return new ArrayList<>(ACTIVE.registries.keySet());
     }
 }

src/main/java/net/minecraftforge/server/command/CommandModList.java

@@ -0,0 +1,45 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.server.command;
+
+import com.mojang.brigadier.builder.ArgumentBuilder;
+import net.minecraft.command.CommandSource;
+import net.minecraft.command.Commands;
+import net.minecraft.util.text.TextComponentTranslation;
+import net.minecraftforge.fml.ModList;
+import net.minecraftforge.fml.loading.moddiscovery.ModInfo;
+
+import java.util.stream.Collectors;
+
+public class CommandModList {
+    static ArgumentBuilder<CommandSource, ?> register()
+    {
+        return Commands.literal("mods")
+                .requires(cs->cs.hasPermissionLevel(0)) //permission
+                .executes(ctx -> {
+                            ctx.getSource().sendFeedback(new TextComponentTranslation("commands.forge.mods.list",
+                                    ModList.get().getMods().stream().map(ModInfo::getModId).collect(Collectors.joining(","))),
+                                    true);
+                            return 0;
+                        }
+                );
+    }
+
+}

src/main/java/net/minecraftforge/server/command/ForgeCommand.java

@@ -35,6 +35,7 @@ public class ForgeCommand
             .then(CommandGenerate.register())
             .then(CommandDimensions.register())
             .then(CommandSetDimension.register())
+            .then(CommandModList.register())
         );
     }
 }