Bump version for RB.

Signed-off-by: cpw <[email protected]>

build.gradle

@@ -197,7 +197,7 @@ project(':forge') {
     }
 
     ext {
-        SPEC_VERSION = '35.0' // This is overwritten by git tag, but here so dev time doesnt explode
+        SPEC_VERSION = '35.1' // This is overwritten by git tag, but here so dev time doesnt explode
         // The new versioning sceme is <MCVersion>-<ForgeMC>.<RB>.<CommitsSinceRB>
         // ForgeMC is a unique identifier for every MC version we have supported.
         // Essentially, the same as the old, except dropping the first number, and the builds are no longer unique.
@@ -879,7 +879,9 @@ project(':forge') {
                 FORGE_NAME: project.name,
                 MC_VERSION: MC_VERSION,
                 MAPPING_CHANNEL: MAPPING_CHANNEL,
-                MAPPING_VERSION: MAPPING_VERSION
+                MAPPING_VERSION: MAPPING_VERSION,
+                FORGE_SPEC_VERSION: SPEC_VERSION.split("\\.")[0],
+                MC_NEXT_VERSION: "1."+((MC_VERSION.split("\\.")[1] as int)+1)
             ])
             rename 'gitignore\\.txt', '.gitignore'
             rename 'gitattributes\\.txt', '.gitattributes'

mdk/src/main/resources/META-INF/mods.toml

@@ -6,7 +6,7 @@
 # The name of the mod loader type to load - for regular FML @Mod mods it should be javafml
 modLoader="javafml" #mandatory
 # A version range to match for said mod loader - for regular FML @Mod it will be the forge version
-loaderVersion="[34,)" #mandatory This is typically bumped every Minecraft version by Forge. See our download page for lists of versions.
+loaderVersion="[@FORGE_SPEC_VERSION@,)" #mandatory This is typically bumped every Minecraft version by Forge. See our download page for lists of versions.
 # The license for you mod. This is mandatory metadata and allows for easier comprehension of your redistributive properties.
 # Review your options at https://choosealicense.com/. All rights reserved is the default copyright stance, and is thus the default here.
 license="All rights reserved"
@@ -17,6 +17,8 @@ issueTrackerURL="http://my.issue.tracker/" #optional
 # The modid of the mod
 modId="examplemod" #mandatory
 # The version number of the mod - there's a few well known ${} variables useable here or just hardcode it
+# ${file.jarVersion} will substitute the value of the Implementation-Version as read from the mod's JAR file metadata
+# see the associated build.gradle script for how to populate this completely automatically during a build
 version="${file.jarVersion}" #mandatory
  # A display name for the mod
 displayName="Example Mod" #mandatory
@@ -45,7 +47,7 @@ Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed mollis lacinia magn
     # Does this dependency have to exist - if not, ordering below must be specified
     mandatory=true #mandatory
     # The version range of the dependency
-    versionRange="[34,)" #mandatory
+    versionRange="[@FORGE_SPEC_VERSION@,)" #mandatory
     # An ordering relationship for the dependency - BEFORE or AFTER required if the relationship is not mandatory
     ordering="NONE"
     # Side this dependency is applied on - BOTH, CLIENT or SERVER
@@ -54,6 +56,7 @@ Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed mollis lacinia magn
 [[dependencies.examplemod]]
     modId="minecraft"
     mandatory=true
-    versionRange="[1.16.3]"
+# This version range declares a minimum of the current minecraft version up to but not including the next major version
+    versionRange="[@MC_VERSION@,@MC_NEXT_VERSION@)"
     ordering="NONE"
     side="BOTH"

patches/minecraft/net/minecraft/client/renderer/WorldRenderer.java.patch

@@ -47,6 +47,15 @@
        this.func_228441_a_(RenderType.func_228643_e_(), p_228426_1_, d0, d1, d2);
        if (this.field_72769_h.func_239132_a_().func_239217_c_()) {
           RenderHelper.func_237533_a_(p_228426_1_.func_227866_c_().func_227870_a_());
+@@ -972,7 +979,7 @@
+       IRenderTypeBuffer.Impl irendertypebuffer$impl = this.field_228415_m_.func_228487_b_();
+ 
+       for(Entity entity : this.field_72769_h.func_217416_b()) {
+-         if ((this.field_175010_j.func_229086_a_(entity, clippinghelper, d0, d1, d2) || entity.func_184215_y(this.field_72777_q.field_71439_g)) && (entity != p_228426_6_.func_216773_g() || p_228426_6_.func_216770_i() || p_228426_6_.func_216773_g() instanceof LivingEntity && ((LivingEntity)p_228426_6_.func_216773_g()).func_70608_bn()) && (!(entity instanceof ClientPlayerEntity) || p_228426_6_.func_216773_g() == entity)) {
++         if ((this.field_175010_j.func_229086_a_(entity, clippinghelper, d0, d1, d2) || entity.func_184215_y(this.field_72777_q.field_71439_g)) && (entity != p_228426_6_.func_216773_g() || p_228426_6_.func_216770_i() || p_228426_6_.func_216773_g() instanceof LivingEntity && ((LivingEntity)p_228426_6_.func_216773_g()).func_70608_bn()) && (!(entity instanceof ClientPlayerEntity) || p_228426_6_.func_216773_g() == entity || (entity == field_72777_q.field_71439_g && !field_72777_q.field_71439_g.func_175149_v()))) { //FORGE: render local player entity when it is not the renderViewEntity
+             ++this.field_72749_I;
+             if (entity.field_70173_aa == 0) {
+                entity.field_70142_S = entity.func_226277_ct_();
 @@ -1010,6 +1017,7 @@
           List<TileEntity> list = worldrenderer$localrenderinformationcontainer.field_178036_a.func_178571_g().func_178485_b();
           if (!list.isEmpty()) {

patches/minecraft/net/minecraft/command/arguments/ArgumentTypes.java.patch

@@ -0,0 +1,11 @@
+--- a/net/minecraft/command/arguments/ArgumentTypes.java
++++ b/net/minecraft/command/arguments/ArgumentTypes.java
+@@ -220,4 +220,8 @@
+          this.field_197481_c = p_i48088_3_;
+       }
+    }
++   @javax.annotation.Nullable public static ResourceLocation getId(ArgumentType<?> type) {
++      Entry<?> entry = func_201040_a(type);
++      return entry == null ? null : entry.field_197481_c;
++   }
+ }

patches/minecraft/net/minecraft/inventory/container/RepairContainer.java.patch

@@ -26,7 +26,7 @@
 +
           if (!itemstack2.func_190926_b()) {
 -            boolean flag = itemstack2.func_77973_b() == Items.field_151134_bR && !EnchantedBookItem.func_92110_g(itemstack2).isEmpty();
-+            if (!net.minecraftforge.common.ForgeHooks.onAnvilChange(this, itemstack, itemstack2, field_234642_c_, field_82857_m, j)) return;
++            if (!net.minecraftforge.common.ForgeHooks.onAnvilChange(this, itemstack, itemstack2, field_234642_c_, field_82857_m, j, this.field_234645_f_)) return;
 +            flag = itemstack2.func_77973_b() == Items.field_151134_bR && !EnchantedBookItem.func_92110_g(itemstack2).isEmpty();
              if (itemstack1.func_77984_f() && itemstack1.func_77973_b().func_82789_a(itemstack, itemstack2)) {
                 int l2 = Math.min(itemstack1.func_77952_i(), itemstack1.func_77958_k() / 4);

patches/minecraft/net/minecraft/network/play/server/SCommandListPacket.java.patch

@@ -1,12 +0,0 @@
---- a/net/minecraft/network/play/server/SCommandListPacket.java
-+++ b/net/minecraft/network/play/server/SCommandListPacket.java
-@@ -119,6 +119,9 @@
-          String s = p_197695_0_.func_150789_c(32767);
-          ArgumentType<?> argumenttype = ArgumentTypes.func_197486_a(p_197695_0_);
-          if (argumenttype == null) {
-+            if ((i & 16) != 0) { // FORGE: Flush unused suggestion data
-+               p_197695_0_.func_192575_l();
-+            }
-             return null;
-          } else {
-             RequiredArgumentBuilder<ISuggestionProvider, ?> requiredargumentbuilder = RequiredArgumentBuilder.argument(s, argumenttype);

patches/minecraft/net/minecraft/server/Main.java.patch

@@ -55,7 +55,16 @@
           SaveFormat saveformat = SaveFormat.func_237269_a_(file1.toPath());
           SaveFormat.LevelSave saveformat$levelsave = saveformat.func_237274_c_(s);
           MinecraftServer.func_240777_a_(saveformat$levelsave);
-@@ -169,6 +176,7 @@
+@@ -142,6 +149,8 @@
+                dimensiongeneratorsettings = optionset.has(optionspec3) ? serverproperties.field_241082_U_.func_236230_k_() : serverproperties.field_241082_U_;
+             }
+ 
++            // Forge: Deserialize the DimensionGeneratorSettings to ensure modded dims are loaded on first server load (see SimpleRegistryCodec#decode). Vanilla behaviour only loads from the server.properties and deserializes only after the 2nd server load.
++            dimensiongeneratorsettings = DimensionGeneratorSettings.field_236201_a_.encodeStart(worldsettingsimport, dimensiongeneratorsettings).flatMap(nbt -> DimensionGeneratorSettings.field_236201_a_.parse(worldsettingsimport, nbt)).getOrThrow(false, errorMsg->{});
+             iserverconfiguration = new ServerWorldInfo(worldsettings, dimensiongeneratorsettings, Lifecycle.stable());
+          }
+ 
+@@ -169,6 +178,7 @@
           Thread thread = new Thread("Server Shutdown Thread") {
              public void run() {
                 dedicatedserver.func_71263_m(true);

patches/minecraft/net/minecraft/server/management/PlayerList.java.patch

@@ -106,7 +106,16 @@
        if (flag2) {
           serverplayerentity.field_71135_a.func_147359_a(new SPlaySoundEffectPacket(SoundEvents.field_232818_ms_, SoundCategory.BLOCKS, (double)blockpos.func_177958_n(), (double)blockpos.func_177956_o(), (double)blockpos.func_177952_p(), 1.0F, 1.0F));
        }
-@@ -786,7 +795,7 @@
+@@ -769,6 +778,8 @@
+          this.field_192055_p.put(uuid, playeradvancements);
+       }
+ 
++      // Forge: don't overwrite active player with a fake one.
++      if (!(p_192054_1_ instanceof net.minecraftforge.common.util.FakePlayer))
+       playeradvancements.func_192739_a(p_192054_1_);
+       return playeradvancements;
+    }
+@@ -786,7 +797,7 @@
     }
  
     public List<ServerPlayerEntity> func_181057_v() {
@@ -115,7 +124,7 @@
     }
  
     @Nullable
-@@ -804,6 +813,7 @@
+@@ -804,6 +815,7 @@
        }
  
        this.func_148540_a(new STagsListPacket(this.field_72400_f.func_244266_aF()));
@@ -123,7 +132,7 @@
        SUpdateRecipesPacket supdaterecipespacket = new SUpdateRecipesPacket(this.field_72400_f.func_199529_aN().func_199510_b());
  
        for(ServerPlayerEntity serverplayerentity : this.field_72404_b) {
-@@ -816,4 +826,12 @@
+@@ -816,4 +828,12 @@
     public boolean func_206257_x() {
        return this.field_72407_n;
     }

patches/minecraft/net/minecraft/world/chunk/storage/ChunkSerializer.java.patch

@@ -17,6 +17,15 @@
                    chunkprimer.func_201637_h(blockpos);
                 }
              }
+@@ -167,7 +168,7 @@
+       Heightmap.func_222690_a(ichunk, enumset);
+       CompoundNBT compoundnbt4 = compoundnbt.func_74775_l("Structures");
+       ichunk.func_201612_a(func_235967_a_(p_222656_1_, compoundnbt4, p_222656_0_.func_72905_C()));
+-      ichunk.func_201606_b(func_227075_a_(p_222656_3_, compoundnbt4));
++      net.minecraftforge.common.ForgeHooks.fixNullStructureReferences(ichunk, func_227075_a_(p_222656_3_, compoundnbt4));
+       if (compoundnbt.func_74767_n("shouldSave")) {
+          ichunk.func_177427_f(true);
+       }
 @@ -183,6 +184,7 @@
        }
  

src/fmllauncher/java/net/minecraftforge/fml/loading/EarlyLoadingException.java

@@ -29,8 +29,6 @@ import java.util.List;
  */
 public class EarlyLoadingException extends RuntimeException {
     public static class ExceptionData {
-
-
         private final IModInfo modInfo;
         private final String i18message;
         private final Object[] args;

src/fmllauncher/java/net/minecraftforge/fml/loading/FMLLoader.java

@@ -34,6 +34,7 @@ import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.fml.loading.moddiscovery.BackgroundScanHandler;
 import net.minecraftforge.fml.loading.moddiscovery.ModDiscoverer;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
+import net.minecraftforge.fml.loading.moddiscovery.ModFileInfo;
 import net.minecraftforge.fml.loading.progress.EarlyProgressVisualization;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.forgespi.Environment;
@@ -53,6 +54,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.BiFunction;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
@@ -214,7 +216,7 @@ public class FMLLoader
         loadingModList = backgroundScanHandler.getLoadingModList();
         commonLaunchHandler.addLibraries(backgroundScanHandler.getModFiles().getOrDefault(IModFile.Type.LIBRARY, Collections.emptyList()));
         progressWindowTick.run();
-        return backgroundScanHandler.getModFiles();
+        return loadingModList.getModFiles().stream().map(ModFileInfo::getFile).collect(Collectors.groupingBy(ModFile::getType));
     }
 
     public static ICoreModProvider getCoreModProvider() {

src/fmllauncher/java/net/minecraftforge/fml/loading/LanguageLoadingProvider.java

@@ -170,7 +170,7 @@ public class LanguageLoadingProvider
             LOGGER.error("Missing language {} version {} wanted by {}", modLoader, modLoaderVersion, languageFileName);
             throw new EarlyLoadingException("Missing language "+modLoader, null, Collections.singletonList(new EarlyLoadingException.ExceptionData("fml.language.missingversion", modLoader, modLoaderVersion, languageFileName, "null")));
         }
-        if (!modLoaderVersion.containsVersion(mlw.getVersion())) {
+        if (!VersionSupportMatrix.testVersionSupportMatrix(modLoaderVersion, modLoader, "languageloader", (llid, range) -> range.containsVersion(mlw.getVersion()))) {
             LOGGER.error("Missing language {} version {} wanted by {}, found {}", modLoader, modLoaderVersion, languageFileName, mlw.getVersion());
             throw new EarlyLoadingException("Missing language "+ modLoader + " matching range "+modLoaderVersion + " found "+mlw.getVersion(), null, Collections.singletonList(new EarlyLoadingException.ExceptionData("fml.language.missingversion", modLoader, modLoaderVersion, languageFileName, mlw.getVersion())));
         }

src/fmllauncher/java/net/minecraftforge/fml/loading/ModSorter.java

@@ -36,17 +36,11 @@ import org.apache.logging.log4j.util.StringBuilderFormattable;
 import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
 
-import java.util.AbstractMap;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
+import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import static net.minecraftforge.fml.loading.LogMarkers.LOADING;
 
@@ -56,6 +50,7 @@ public class ModSorter
     private List<ModFile> modFiles;
     private List<ModInfo> sortedList;
     private Map<String, ModInfo> modIdNameLookup;
+    private List<ModFile> forgeAndMC;
 
     private ModSorter(final List<ModFile> modFiles)
     {
@@ -65,21 +60,41 @@ public class ModSorter
     public static LoadingModList sort(List<ModFile> mods)
     {
         final ModSorter ms = new ModSorter(mods);
-        EarlyLoadingException earlyLoadingException = null;
         try {
-            ms.findLanguages();
             ms.buildUniqueList();
-            ms.verifyDependencyVersions();
-            ms.sort();
-        } catch (EarlyLoadingException ele) {
-            earlyLoadingException = ele;
-            ms.sortedList = Collections.emptyList();
+        } catch (EarlyLoadingException e) {
+            // We cannot build any list with duped mods. We have to abort immediately and report it
+            return LoadingModList.of(ms.forgeAndMC, ms.forgeAndMC.stream().map(mf->(ModInfo)mf.getModInfos().get(0)).collect(Collectors.toList()), e);
+        }
+        // try and locate languages and validate dependencies
+        List<EarlyLoadingException.ExceptionData> missingLangs = ms.findLanguages();
+        List<EarlyLoadingException.ExceptionData> missingDeps = ms.verifyDependencyVersions();
+        final List<ExceptionData> failedList = Stream.concat(missingLangs.stream(), missingDeps.stream()).collect(Collectors.toList());
+        // if we miss one or the other, we abort now
+        if (!failedList.isEmpty()) {
+            return LoadingModList.of(ms.forgeAndMC, ms.forgeAndMC.stream().map(mf->(ModInfo)mf.getModInfos().get(0)).collect(Collectors.toList()), new EarlyLoadingException("failure to validate mod list", null, failedList));
+        } else {
+            // Otherwise, lets try and sort the modlist and proceed
+            EarlyLoadingException earlyLoadingException = null;
+            try {
+                ms.sort();
+            } catch (EarlyLoadingException e) {
+                earlyLoadingException = e;
+            }
+            return LoadingModList.of(ms.modFiles, ms.sortedList, earlyLoadingException);
         }
-        return LoadingModList.of(ms.modFiles, ms.sortedList, earlyLoadingException);
     }
 
-    private void findLanguages() {
-        modFiles.forEach(ModFile::identifyLanguage);
+    private List<EarlyLoadingException.ExceptionData> findLanguages() {
+        List<EarlyLoadingException.ExceptionData> errorData = new ArrayList<>();
+        modFiles.forEach(modFile -> {
+            try {
+                modFile.identifyLanguage();
+            } catch (EarlyLoadingException e) {
+                errorData.addAll(e.getAllData());
+            }
+        });
+        return errorData;
     }
 
     @SuppressWarnings("UnstableApiUsage")
@@ -167,6 +182,11 @@ public class ModSorter
                 .stream()
                 .collect(Collectors.groupingBy(mf -> mf.getModInfos().get(0).getModId()));
 
+        // Capture forge and MC here, so we can keep them for later
+        forgeAndMC = new ArrayList<>();
+        forgeAndMC.add((ModFile)modFilesByFirstId.get("minecraft").get(0));
+        forgeAndMC.add((ModFile)modFilesByFirstId.get("forge").get(0));
+
         // Select the newest by artifact version sorting of non-unique files thus identified
         this.modFiles = modFilesByFirstId.entrySet().stream()
                 .map(this::selectNewestModInfo)
@@ -213,7 +233,7 @@ public class ModSorter
         return new AbstractMap.SimpleImmutableEntry<>(fullList.getKey(), modInfoList.get(0));
     }
 
-    private void verifyDependencyVersions()
+    private List<EarlyLoadingException.ExceptionData> verifyDependencyVersions()
     {
         final Map<String, ArtifactVersion> modVersions = modFiles
                 .stream()
@@ -237,24 +257,24 @@ public class ModSorter
         LOGGER.debug(LOADING, "Found {} mandatory requirements", mandatoryModVersions.size());
         final Set<IModInfo.ModVersion> missingVersions = mandatoryModVersions
                 .stream()
-                .filter(mv->this.modVersionMatches(mv, modVersions))
+                .filter(mv->this.modVersionNotContained(mv, modVersions))
                 .collect(Collectors.toSet());
         LOGGER.debug(LOADING, "Found {} mandatory mod requirements missing", missingVersions.size());
 
         if (!missingVersions.isEmpty()) {
-            final List<EarlyLoadingException.ExceptionData> exceptionData = missingVersions
+            return missingVersions
                     .stream()
-                    .map(mv -> new EarlyLoadingException.ExceptionData("fml.modloading.missingdependency", mv.getOwner(),
+                    .map(mv -> new ExceptionData("fml.modloading.missingdependency", mv.getOwner(),
                             mv.getModId(), mv.getOwner().getModId(), mv.getVersionRange(),
                             modVersions.getOrDefault(mv.getModId(), new DefaultArtifactVersion("null"))))
                     .collect(Collectors.toList());
-            throw new EarlyLoadingException("Missing mods", null, exceptionData);
         }
+        return Collections.emptyList();
     }
 
-    private boolean modVersionMatches(final IModInfo.ModVersion mv, final Map<String, ArtifactVersion> modVersions)
+    private boolean modVersionNotContained(final IModInfo.ModVersion mv, final Map<String, ArtifactVersion> modVersions)
     {
-        return !(modVersions.containsKey(mv.getModId()) &&
-                (mv.getVersionRange().containsVersion(modVersions.get(mv.getModId())) || modVersions.get(mv.getModId()).toString().equals("NONE")));
+        return !(VersionSupportMatrix.testVersionSupportMatrix(mv.getVersionRange(), mv.getModId(), "mod", (modId, range) -> modVersions.containsKey(modId) &&
+                (range.containsVersion(modVersions.get(modId)) || modVersions.get(modId).toString().equals("NONE"))));
     }
 }

src/fmllauncher/java/net/minecraftforge/fml/loading/VersionSupportMatrix.java

@@ -0,0 +1,24 @@
+package net.minecraftforge.fml.loading;
+
+import net.minecraftforge.forgespi.language.MavenVersionAdapter;
+import org.apache.maven.artifact.versioning.ArtifactVersion;
+import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
+import org.apache.maven.artifact.versioning.VersionRange;
+
+import java.util.HashMap;
+import java.util.function.BiPredicate;
+
+public class VersionSupportMatrix {
+    private static final HashMap<String, ArtifactVersion> overrideVersions = new HashMap<>();
+    static {
+        final ArtifactVersion version = new DefaultArtifactVersion(FMLLoader.mcVersion);
+        if (MavenVersionAdapter.createFromVersionSpec("[1.16.4]").containsVersion(version)) {
+            overrideVersions.put("languageloader.javafml", new DefaultArtifactVersion("34")); // we also work with javafml 34
+            overrideVersions.put("mod.minecraft", new DefaultArtifactVersion("1.16.3")); // we work with anything declaring 1.16.3
+            overrideVersions.put("mod.forge", new DefaultArtifactVersion("34.1.42")); // we work with anything that supports forge 34.1.42
+        }
+    }
+    public static <T> boolean testVersionSupportMatrix(VersionRange declaredRange, String lookupId, String type, BiPredicate<String, VersionRange> standardLookup) {
+        return standardLookup.test(lookupId, declaredRange) || overrideVersions.containsKey(type +"." +lookupId) && declaredRange.containsVersion(overrideVersions.get(type +"." +lookupId));
+    }
+}

src/fmllauncher/java/net/minecraftforge/fml/loading/progress/StartupMessageManager.java

@@ -24,15 +24,12 @@ import com.google.common.base.CharMatcher;
 import org.apache.commons.lang3.tuple.Pair;
 
 import java.util.*;
-import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 public class StartupMessageManager {
-    private static final EnumMap<MessageType, List<Message>> messages = new EnumMap<>(MessageType.class);
-    static {
-        Arrays.stream(MessageType.values()).forEach(mt->messages.computeIfAbsent(mt, k->new CopyOnWriteArrayList<>()));
-    }
+
+    private static volatile EnumMap<MessageType, List<Message>> messages = new EnumMap<>(MessageType.class);
 
     public static List<Pair<Integer,Message>> getMessages() {
         final long ts = System.nanoTime();
@@ -88,22 +85,42 @@ public class StartupMessageManager {
         }
     }
 
+    private synchronized static void addMessage(MessageType type, String message, int maxSize)
+    {
+        EnumMap<MessageType, List<Message>> newMessages = new EnumMap<>(messages);
+        newMessages.compute(type, (key, existingList) -> {
+            List<Message> newList = new ArrayList<>();
+            if (existingList != null)
+            {
+                if (maxSize < 0)
+                {
+                    newList.addAll(existingList);
+                }
+                else
+                {
+                    newList.addAll(existingList.subList(0, Math.min(existingList.size(), maxSize)));
+                }
+            }
+            newList.add(new Message(message, type));
+            return newList;
+        });
+        messages = newMessages;
+    }
+
     public static void addModMessage(final String message) {
         final String safeMessage = Ascii.truncate(CharMatcher.ascii().retainFrom(message),80,"~");
-        final List<Message> messages = StartupMessageManager.messages.get(MessageType.MOD);
-        messages.subList(0, Math.max(0, messages.size() - 20)).clear();
-        messages.add(new Message(safeMessage, MessageType.MOD));
+        addMessage(MessageType.MOD, safeMessage, 20);
     }
 
     public static Optional<Consumer<String>> modLoaderConsumer() {
-        return Optional.of(s-> messages.get(MessageType.ML).add(new Message(s, MessageType.ML)));
+        return Optional.of(s-> addMessage(MessageType.ML, s, -1));
     }
 
     public static Optional<Consumer<String>> locatorConsumer() {
-        return Optional.of(s -> messages.get(MessageType.LOC).add(new Message(s, MessageType.LOC)));
+        return Optional.of(s -> addMessage(MessageType.LOC, s, -1));
     }
 
     public static Optional<Consumer<String>> mcLoaderConsumer() {
-        return Optional.of(s-> messages.get(MessageType.MC).add(new Message(s, MessageType.MC)));
+        return Optional.of(s-> addMessage(MessageType.MC, s, -1));
     }
 }

src/main/java/net/minecraftforge/client/event/ClientPlayerChangeGameModeEvent.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.event;
 
 import net.minecraft.client.network.play.NetworkPlayerInfo;

src/main/java/net/minecraftforge/client/gui/ForgeIngameGui.java

@@ -112,7 +112,7 @@ public class ForgeIngameGui extends IngameGui
         this.scaledHeight = this.mc.getMainWindow().getScaledHeight();
         eventParent = new RenderGameOverlayEvent(mStack, partialTicks, this.mc.getMainWindow());
         renderHealthMount = mc.player.getRidingEntity() instanceof LivingEntity;
-        renderFood = mc.player.getRidingEntity() == null;
+        renderFood = !renderHealthMount;
         renderJumpBar = mc.player.isRidingHorse();
 
         right_height = 39;

src/main/java/net/minecraftforge/client/model/generators/CustomLoaderBuilder.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.model.generators;
 
 import com.google.common.base.Preconditions;

src/main/java/net/minecraftforge/client/model/generators/loaders/CompositeModelBuilder.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.model.generators.loaders;
 
 import com.google.common.base.Preconditions;

src/main/java/net/minecraftforge/client/model/generators/loaders/DynamicBucketModelBuilder.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.model.generators.loaders;
 
 import com.google.common.base.Preconditions;

src/main/java/net/minecraftforge/client/model/generators/loaders/ItemLayersModelBuilder.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.model.generators.loaders;
 
 import com.google.common.base.Preconditions;

src/main/java/net/minecraftforge/client/model/generators/loaders/MultiLayerModelBuilder.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.model.generators.loaders;
 
 import com.google.common.base.Preconditions;

src/main/java/net/minecraftforge/client/model/generators/loaders/OBJLoaderBuilder.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.model.generators.loaders;
 
 import com.google.common.base.Preconditions;

src/main/java/net/minecraftforge/client/model/generators/loaders/SeparatePerspectiveModelBuilder.java

@@ -1,3 +1,22 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.client.model.generators.loaders;
 
 import com.google.common.base.Preconditions;

src/main/java/net/minecraftforge/common/ForgeHooks.java

@@ -43,6 +43,8 @@ import com.mojang.serialization.codecs.RecordCodecBuilder;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+
+import it.unimi.dsi.fastutil.longs.LongSet;
 import net.minecraft.advancements.Advancement;
 import net.minecraft.block.Block;
 import net.minecraft.block.material.Material;
@@ -91,6 +93,8 @@ import net.minecraft.potion.PotionUtils;
 import net.minecraft.stats.Stats;
 import net.minecraft.util.math.vector.Vector3d;
 import net.minecraft.util.text.*;
+import net.minecraft.world.chunk.IChunk;
+import net.minecraft.world.gen.feature.structure.Structure;
 import net.minecraft.world.spawner.AbstractSpawner;
 import net.minecraft.tileentity.FurnaceTileEntity;
 import net.minecraft.tileentity.TileEntity;
@@ -177,7 +181,7 @@ public class ForgeHooks
     {
         //state = state.getActualState(world, pos);
         if (!state.getRequiresTool())
-            return true;
+            return ForgeEventFactory.doPlayerHarvestCheck(player, state, true);
 
         ItemStack stack = player.getHeldItemMainhand();
         ToolType tool = state.getHarvestTool();
@@ -672,9 +676,15 @@ public class ForgeHooks
         return ret;
     }
 
+    @Deprecated // TODO: Remove 1.17 - Use player-contextual version below.
     public static boolean onAnvilChange(RepairContainer container, @Nonnull ItemStack left, @Nonnull ItemStack right, IInventory outputSlot, String name, int baseCost)
     {
-        AnvilUpdateEvent e = new AnvilUpdateEvent(left, right, name, baseCost);
+        return onAnvilChange(container, left, right, outputSlot, name, baseCost, null);
+    }
+
+    public static boolean onAnvilChange(RepairContainer container, @Nonnull ItemStack left, @Nonnull ItemStack right, IInventory outputSlot, String name, int baseCost, PlayerEntity player)
+    {
+        AnvilUpdateEvent e = new AnvilUpdateEvent(left, right, name, baseCost, player);
         if (MinecraftForge.EVENT_BUS.post(e)) return false;
         if (e.getOutput().isEmpty()) return true;
 
@@ -1226,4 +1236,18 @@ public class ForgeHooks
         modpacks.add("vanilla");
         return modpacks;
     }
+
+    /**
+     * Fixes MC-194811
+     * When a structure mod is removed, this map may contain null keys. This will make the world unable to save if this persists.
+     * If we remove a structure from the save data in this way, we then mark the chunk for saving
+     */
+    public static void fixNullStructureReferences(IChunk chunk, Map<Structure<?>, LongSet> structureReferences)
+    {
+        if (structureReferences.remove(null) != null)
+        {
+            chunk.setModified(true);
+        }
+        chunk.setStructureReferences(structureReferences);
+    }
 }

src/main/java/net/minecraftforge/common/ForgeMod.java

@@ -19,6 +19,9 @@
 
 package net.minecraftforge.common;
 
+import net.minecraft.command.arguments.ArgumentSerializer;
+import net.minecraft.command.arguments.ArgumentTypes;
+import net.minecraft.command.arguments.IArgumentSerializer;
 import net.minecraft.entity.ai.attributes.Attribute;
 import net.minecraft.entity.ai.attributes.RangedAttribute;
 import net.minecraft.util.SoundEvent;
@@ -34,6 +37,8 @@ import net.minecraftforge.fml.event.server.FMLServerStoppingEvent;
 import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.registries.DeferredRegister;
+import net.minecraftforge.server.command.EnumArgument;
+import net.minecraftforge.server.command.ModIdArgument;
 import net.minecraftforge.versions.forge.ForgeVersion;
 import net.minecraftforge.versions.mcp.MCPVersion;
 
@@ -139,13 +144,14 @@ public class ForgeMod implements WorldPersistenceHooks.WorldPersistenceHook
 
         VersionChecker.startVersionCheck();
 
-        /*
-         * We can't actually add any of these, because vanilla clients will choke on unknown argument types
-         * So our custom arguments will not validate client-side, but they do still work
-        ArgumentTypes.register("forge:enum", EnumArgument.class, new EnumArgument.Serializer());
+        registerArgumentTypes();
+    }
+
+    @SuppressWarnings({"unchecked", "rawtypes"})
+    private void registerArgumentTypes()
+    {
+        ArgumentTypes.register("forge:enum", EnumArgument.class, (IArgumentSerializer) new EnumArgument.Serializer());
         ArgumentTypes.register("forge:modid", ModIdArgument.class, new ArgumentSerializer<>(ModIdArgument::modIdArgument));
-        ArgumentTypes.register("forge:structure_type", StructureArgument.class, new ArgumentSerializer<>(StructureArgument::structure));
-        */
     }
 
     public void serverStopping(FMLServerStoppingEvent evt)

src/main/java/net/minecraftforge/event/AnvilUpdateEvent.java

@@ -19,52 +19,150 @@
 
 package net.minecraftforge.event;
 
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.inventory.container.RepairContainer;
+import net.minecraft.item.ItemStack;
 import net.minecraftforge.eventbus.api.Cancelable;
 import net.minecraftforge.eventbus.api.Event;
-import net.minecraft.item.ItemStack;
 
-import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * 
- * AnvilUpdateEvent is fired when a player places items in both the left and right slots of a anvil.
- * If the event is canceled, vanilla behavior will not run, and the output will be set to null.
- * If the event is not canceled, but the output is not null, it will set the output and not run vanilla behavior.
- * if the output is null, and the event is not canceled, vanilla behavior will execute.
+ * AnvilUpdateEvent is fired when the inputs (either input stack, or the name) to an anvil are changed. <br> 
+ * It is called from {@link RepairContainer#updateRepairOutput}. <br>
+ * If the event is canceled, vanilla behavior will not run, and the output will be set to {@link ItemStack#EMPTY}. <br>
+ * If the event is not canceled, but the output is not empty, it will set the output and not run vanilla behavior. <br>
+ * if the output is empty, and the event is not canceled, vanilla behavior will execute. <br>
  */
 @Cancelable
 public class AnvilUpdateEvent extends Event
 {
-    @Nonnull
-    private final ItemStack left;  // The left side of the input
-    @Nonnull
-    private final ItemStack right; // The right side of the input
-    private final String name;     // The name to set the item, if the user specified one.
-    @Nonnull
-    private ItemStack output;      // Set this to set the output stack
-    private int cost;              // The base cost, set this to change it if output != null
-    private int materialCost; // The number of items from the right slot to be consumed during the repair. Leave as 0 to consume the entire stack.
 
-    public AnvilUpdateEvent(@Nonnull ItemStack left, @Nonnull ItemStack right, String name, int cost)
+    private final ItemStack left;
+    private final ItemStack right;
+    private final String name;
+    private ItemStack output;
+    private int cost;
+    private int materialCost;
+    @Nullable // TODO: Remove 1.17 - Nullable only in the instance that a mod uses the deprecated ctor.
+    private final PlayerEntity player;
+
+    @Deprecated //TODO: Remove 1.17 - Use Player-contextual constructor below.
+    public AnvilUpdateEvent(ItemStack left, ItemStack right, String name, int cost)
+    {
+        this(left, right, name, cost, null);
+    }
+
+    public AnvilUpdateEvent(ItemStack left, ItemStack right, String name, int cost, PlayerEntity player)
     {
         this.left = left;
         this.right = right;
         this.output = ItemStack.EMPTY;
         this.name = name;
+        this.player = player;
         this.setCost(cost);
         this.setMaterialCost(0);
     }
 
-    @Nonnull
-    public ItemStack getLeft() { return left; }
-    @Nonnull
-    public ItemStack getRight() { return right; }
-    public String getName() { return name; }
-    @Nonnull
-    public ItemStack getOutput() { return output; }
-    public void setOutput(@Nonnull ItemStack output) { this.output = output; }
-    public int getCost() { return cost; }
-    public void setCost(int cost) { this.cost = cost; }
-    public int getMaterialCost() { return materialCost; }
-    public void setMaterialCost(int materialCost) { this.materialCost = materialCost; }
+    /**
+     * @return The item in the left input (leftmost) anvil slot.
+     */
+    public ItemStack getLeft()
+    {
+        return left;
+    }
+
+    /**
+     * @return The item in the right input (center) anvil slot.
+     */
+    public ItemStack getRight()
+    {
+        return right;
+    }
+
+    /**
+     * This is the name as sent by the client.  It may be null if none has been sent. <br>
+     * If empty, it indicates the user wishes to clear the custom name from the item.
+     * @return The name that the output item will be set to, if applicable.
+     */
+    @Nullable
+    public String getName()
+    {
+        return name;
+    }
+
+    /**
+     * This is the output as determined by the event, not by the vanilla behavior between these two items. <br>
+     * If you are the first receiver of this event, it is guaranteed to be empty. <br>
+     * It will only be non-empty if changed by an event handler. <br>
+     * If this event is cancelled, this output stack is discarded.
+     * @return The item to set in the output (rightmost) anvil slot.
+     */
+    public ItemStack getOutput() 
+    {
+        return output;
+    }
+
+    /**
+     * Sets the output slot to a specific itemstack.
+     * @param output The stack to change the output to.
+     */
+    public void setOutput(ItemStack output)
+    {
+        this.output = output;
+    }
+
+    /**
+     * This is the level cost of this anvil operation. <br> 
+     * When unchanged, it is guaranteed to be left.getRepairCost() + right.getRepairCost().
+     * @return The level cost of this anvil operation.
+     */
+    public int getCost()
+    {
+        return cost;
+    }
+
+    /**
+     * Changes the level cost of this operation. <br>
+     * The level cost does prevent the output from being available.  <br>
+     * That is, a player without enough experience may not take the output.
+     * @param cost The new level cost.
+     */
+    public void setCost(int cost)
+    {
+        this.cost = cost;
+    }
+
+    /**
+     * The material cost is how many units of the right input stack are consumed.
+     * @return The material cost of this anvil operation.
+     */
+    public int getMaterialCost()
+    {
+        return materialCost;
+    }
+
+    /**
+     * Sets how many right inputs are consumed. <br>
+     * A material cost of zero consumes the entire stack. <br>
+     * A material cost higher than the count of the right stack
+     * consumes the entire stack. <br>
+     * The material cost does not prevent the output from being available.
+     * @param materialCost The new material cost.
+     */
+    public void setMaterialCost(int materialCost)
+    {
+        this.materialCost = materialCost;
+    }
+
+    /**
+     * Nullable in the case someone is using the deprecated constructor.
+     * @return The player using this anvil container.
+     */
+    @Nullable // TODO: Remove 1.17
+    public PlayerEntity getPlayer()
+    {
+        return this.player;
+    }
 }

src/main/java/net/minecraftforge/fluids/FluidStack.java

@@ -19,12 +19,15 @@
 
 package net.minecraftforge.fluids;
 
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
 import net.minecraft.fluid.Fluid;
 import net.minecraft.fluid.Fluids;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.CompoundNBT;
 import net.minecraft.network.PacketBuffer;
 import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.registry.Registry;
 import net.minecraft.util.text.ITextComponent;
 import net.minecraftforge.common.util.Constants;
 import net.minecraftforge.registries.ForgeRegistries;
@@ -36,6 +39,8 @@ import javax.annotation.Nullable;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+import java.util.Optional;
+
 /**
  * ItemStack substitute for Fluids.
  *
@@ -50,6 +55,18 @@ public class FluidStack
 
     public static final FluidStack EMPTY = new FluidStack(Fluids.EMPTY, 0);
 
+    public static final Codec<FluidStack> CODEC = RecordCodecBuilder.create(
+            instance -> instance.group(
+                    Registry.FLUID.fieldOf("FluidName").forGetter(FluidStack::getFluid),
+                    Codec.INT.fieldOf("Amount").forGetter(FluidStack::getAmount),
+                    CompoundNBT.CODEC.optionalFieldOf("Tag").forGetter(stack -> Optional.ofNullable(stack.getTag()))
+            ).apply(instance, (fluid, amount, tag) -> {
+                FluidStack stack = new FluidStack(fluid, amount);
+                tag.ifPresent(stack::setTag);
+                return stack;
+            })
+    );
+
     private boolean isEmpty;
     private int amount;
     private CompoundNBT tag;

src/main/java/net/minecraftforge/fml/ExtensionPoint.java

@@ -40,6 +40,33 @@ public class ExtensionPoint<T>
      *
      * The supplier provides my "local" version for sending across the network or writing to disk
      * The predicate tests the version from a remote instance or save for acceptability (Boolean is true for network, false for local save)
+     * and returns true if the version is compatible.
+     *
+     * <p>Return {@link net.minecraftforge.fml.network.FMLNetworkConstants#IGNORESERVERONLY} in the supplier, if you wish to be ignored
+     * as a server side only mod.</p>
+     * <p>Return true in the predicate for all values of the input string (when network boolean is true) if you are client side,
+     * and don't care about matching any potential server version.</p>
+     *
+     * <p>
+     * Examples: A server only mod
+     *
+     * <code><pre>
+     *     registerExtensionPoint(DISPLAYTEST, ()->Pair.of(
+     *      ()->FMLNetworkConstants.IGNORESERVERONLY, // ignore me, I'm a server only mod
+     *      (s,b)->true // i accept anything from the server or the save, if I'm asked
+     *     )
+     * </pre></code>
+     * </p>
+     * <p>
+     * Examples: A client only mod
+     * <code><pre>
+     *     registerExtensionPoint(DISPLAYTEST, ()->Pair.of(
+     *      ()->"anything. i don't care", // if i'm actually on the server, this string is sent but i'm a client only mod, so it won't be
+     *      (remoteversionstring,networkbool)->networkbool // i accept anything from the server, by returning true if it's asking about the server
+     *     )
+     * </pre></code>
+     * </p>
+     *
      */
     public static final ExtensionPoint<Pair<Supplier<String>, BiPredicate<String, Boolean>>> DISPLAYTEST = new ExtensionPoint<>();
 

src/main/java/net/minecraftforge/fml/ModContainer.java

@@ -75,6 +75,16 @@ public abstract class ModContainer
                 (incoming, isNetwork)->Objects.equals(incoming, this.modInfo.getVersion().toString())));
     }
 
+    /**
+     * Errored container state, used for filtering. Does nothing.
+     */
+    ModContainer()
+    {
+        this.modLoadingStage = ModLoadingStage.ERROR;
+        modId = "BROKEN";
+        namespace = "BROKEN";
+        modInfo = null;
+    }
     /**
      * @return the modid for this mod
      */

src/main/java/net/minecraftforge/fml/ModLoader.java

@@ -33,6 +33,7 @@ import net.minecraftforge.fml.loading.LoadingModList;
 import net.minecraftforge.fml.loading.moddiscovery.InvalidModIdentifier;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
 import net.minecraftforge.fml.loading.moddiscovery.ModFileInfo;
+import net.minecraftforge.fml.loading.moddiscovery.ModInfo;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.fml.network.FMLNetworkConstants;
 import net.minecraftforge.fml.network.NetworkRegistry;
@@ -268,8 +269,10 @@ public class ModLoader
         final Map<String, IModInfo> modInfoMap = modFile.getModFileInfo().getMods().stream().collect(Collectors.toMap(IModInfo::getModId, Function.identity()));
 
         LOGGER.debug(LOADING, "ModContainer is {}", ModContainer.class.getClassLoader());
-        final List<ModContainer> containers = modFile.getScanResult().getTargets().entrySet().stream().
-                map(e -> buildModContainerFromTOML(modFile, modClassLoader, modInfoMap, e))
+        final List<ModContainer> containers = modFile.getScanResult().getTargets()
+                .entrySet()
+                .stream()
+                .map(e -> buildModContainerFromTOML(modFile, modClassLoader, modInfoMap, e))
                 .filter(Objects::nonNull)
                 .collect(Collectors.toList());
         if (containers.size() != modInfoMap.size()) {
@@ -279,7 +282,8 @@ public class ModLoader
                     modInfoMap.size(), modInfoMap.values().stream().map(IModInfo::getModId).sorted().collect(Collectors.toList()));
             loadingExceptions.add(new ModLoadingException(null, ModLoadingStage.CONSTRUCT, "fml.modloading.missingclasses", null, modFile.getFilePath()));
         }
-        return containers;
+        // remove errored mod containers
+        return containers.stream().filter(mc -> mc.modLoadingStage != ModLoadingStage.ERROR).collect(Collectors.toList());
     }
 
     private ModContainer buildModContainerFromTOML(final ModFile modFile, final TransformingClassLoader modClassLoader, final Map<String, IModInfo> modInfoMap, final Map.Entry<String, ? extends IModLanguageProvider.IModLanguageLoader> idToProviderEntry) {
@@ -291,9 +295,10 @@ public class ModLoader
                     orElseThrow(()->new ModLoadingException(null, ModLoadingStage.CONSTRUCT, "fml.modloading.missingmetadata", null, modId));
             return languageLoader.loadMod(info, modClassLoader, modFile.getScanResult());
         } catch (ModLoadingException mle) {
-            // exceptions are caught and added to the error list for later handling. Null is returned here.
+            // exceptions are caught and added to the error list for later handling
             loadingExceptions.add(mle);
-            return null;
+            // return an errored container instance here, because we tried and failed building a container.
+            return new ErroredModContainer();
         }
     }
 
@@ -336,4 +341,20 @@ public class ModLoader
     public static boolean isDataGenRunning () {
         return runningDataGen;
     }
+
+    private static class ErroredModContainer extends ModContainer {
+        public ErroredModContainer() {
+            super();
+        }
+
+        @Override
+        public boolean matches(final Object mod) {
+            return false;
+        }
+
+        @Override
+        public Object getMod() {
+            return null;
+        }
+    }
 }

src/main/java/net/minecraftforge/fml/javafmlmod/FMLJavaModLanguageProvider.java

@@ -19,6 +19,10 @@
 
 package net.minecraftforge.fml.javafmlmod;
 
+import cpw.mods.modlauncher.api.LamdbaExceptionUtils;
+import net.minecraftforge.fml.ModLoadingException;
+import net.minecraftforge.fml.ModLoadingStage;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.forgespi.language.ILifecycleEvent;
 import net.minecraftforge.forgespi.language.IModLanguageProvider;
 import net.minecraftforge.forgespi.language.IModInfo;
@@ -39,7 +43,6 @@ import static net.minecraftforge.fml.Logging.*;
 
 public class FMLJavaModLanguageProvider implements IModLanguageProvider
 {
-
     private static final Logger LOGGER = LogManager.getLogger();
 
     private static class FMLModTarget implements IModLanguageProvider.IModLanguageLoader {
@@ -72,10 +75,24 @@ public class FMLJavaModLanguageProvider implements IModLanguageProvider
                 final Constructor<?> constructor = fmlContainer.getConstructor(IModInfo.class, String.class, ClassLoader.class, ModFileScanData.class);
                 return (T)constructor.newInstance(info, className, modClassLoader, modFileScanResults);
             }
-            catch (NoSuchMethodException | ClassNotFoundException | InstantiationException | IllegalAccessException | InvocationTargetException e)
+            // ALL exception handling has to be done through the classloader, because we're loaded in the wrong context, so any classes we just blind load will be in the wrong
+            // class loading context. Funky but works.
+            catch (InvocationTargetException e) {
+                LOGGER.fatal(LOADING, "Failed to build mod", e);
+                final Class<RuntimeException> mle = (Class<RuntimeException>)LamdbaExceptionUtils.uncheck(()->Class.forName("net.minecraftforge.fml.ModLoadingException", true, Thread.currentThread().getContextClassLoader()));
+                if (mle.isInstance(e.getTargetException())) {
+                    throw mle.cast(e.getTargetException());
+                } else {
+                    final Class<ModLoadingStage> mls = (Class<ModLoadingStage>) LamdbaExceptionUtils.uncheck(()->Class.forName("net.minecraftforge.fml.ModLoadingStage", true, Thread.currentThread().getContextClassLoader()));
+                    throw LamdbaExceptionUtils.uncheck(()->LamdbaExceptionUtils.uncheck(()->mle.getConstructor(IModInfo.class, mls, String.class, Throwable.class)).newInstance(info, Enum.valueOf(mls, "CONSTRUCT"), "fml.modloading.failedtoloadmodclass", e));
+                }
+            }
+            catch (NoSuchMethodException | ClassNotFoundException | InstantiationException | IllegalAccessException e)
             {
                 LOGGER.fatal(LOADING,"Unable to load FMLModContainer, wut?", e);
-                throw new RuntimeException(e);
+                final Class<RuntimeException> mle = (Class<RuntimeException>)LamdbaExceptionUtils.uncheck(()->Class.forName("net.minecraftforge.fml.ModLoadingException", true, Thread.currentThread().getContextClassLoader()));
+                final Class<ModLoadingStage> mls = (Class<ModLoadingStage>) LamdbaExceptionUtils.uncheck(()->Class.forName("net.minecraftforge.fml.ModLoadingStage", true, Thread.currentThread().getContextClassLoader()));
+                throw LamdbaExceptionUtils.uncheck(()->LamdbaExceptionUtils.uncheck(()->mle.getConstructor(IModInfo.class, mls, String.class, Throwable.class)).newInstance(info, Enum.valueOf(mls, "CONSTRUCT"), "fml.modloading.failedtoloadmodclass", e));
             }
         }
     }

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

@@ -27,7 +27,8 @@ public enum ConnectionType
 
     private final Function<String, Integer> versionExtractor;
 
-    ConnectionType(Function<String, Integer> versionExtractor) {
+    ConnectionType(Function<String, Integer> versionExtractor)
+    {
         this.versionExtractor = versionExtractor;
     }
 
@@ -36,7 +37,14 @@ public enum ConnectionType
         return vers.startsWith(FMLNetworkConstants.FMLNETMARKER) ? MODDED : VANILLA;
     }
 
-    public int getFMLVersionNumber(final String fmlVersion) {
+    public int getFMLVersionNumber(final String fmlVersion)
+    {
         return versionExtractor.apply(fmlVersion);
     }
+
+    public boolean isVanilla()
+    {
+        return this == VANILLA;
+    }
+
 }

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

@@ -27,6 +27,8 @@ import java.util.function.Consumer;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
 import net.minecraft.tags.ITagCollection;
 import net.minecraft.tags.ITagCollectionSupplier;
 import net.minecraft.util.text.StringTextComponent;
@@ -62,7 +64,17 @@ public class NetworkHooks
 
     public static ConnectionType getConnectionType(final Supplier<NetworkManager> connection)
     {
-        return ConnectionType.forVersionFlag(connection.get().channel().attr(FMLNetworkConstants.FML_NETVERSION).get());
+        return getConnectionType(connection.get().channel());
+    }
+
+    public static ConnectionType getConnectionType(ChannelHandlerContext context)
+    {
+        return getConnectionType(context.channel());
+    }
+
+    private static ConnectionType getConnectionType(Channel channel)
+    {
+        return ConnectionType.forVersionFlag(channel.attr(FMLNetworkConstants.FML_NETVERSION).get());
     }
 
     public static IPacket<?> getEntitySpawningPacket(Entity entity)

src/main/java/net/minecraftforge/fml/server/ServerLifecycleHooks.java

@@ -68,6 +68,7 @@ import net.minecraftforge.fml.loading.moddiscovery.ModFile;
 import net.minecraftforge.fml.packs.ModFileResourcePack;
 import net.minecraftforge.fml.packs.ResourcePackLoader;
 import net.minecraftforge.forgespi.language.IModInfo;
+import net.minecraftforge.network.VanillaConnectionNetworkFilter;
 import net.minecraftforge.registries.GameData;
 
 public class ServerLifecycleHooks
@@ -168,6 +169,7 @@ public class ServerLifecycleHooks
         if (packet.getRequestedState() == ProtocolType.STATUS) return true;
 
         NetworkHooks.registerServerLoginChannel(manager, packet);
+        VanillaConnectionNetworkFilter.injectIfNecessary(manager);
         return true;
 
     }

src/main/java/net/minecraftforge/network/CommandTreeCleaner.java

@@ -0,0 +1,89 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.network;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Predicate;
+
+import com.mojang.brigadier.arguments.ArgumentType;
+import com.mojang.brigadier.builder.ArgumentBuilder;
+import com.mojang.brigadier.tree.ArgumentCommandNode;
+import com.mojang.brigadier.tree.CommandNode;
+import com.mojang.brigadier.tree.RootCommandNode;
+
+class CommandTreeCleaner
+{
+
+    /**
+     * Cleans the command tree starting at the given root node from any argument types that do not match the given predicate.
+     * Any {@code ArgumentCommandNode}s that have an unmatched argument type will be stripped from the tree.
+     * @return A new command tree, stripped of any unmatched argument types
+     */
+    public static <S> RootCommandNode<S> cleanArgumentTypes(RootCommandNode<S> root, Predicate<ArgumentType<?>> argumentTypeFilter)
+    {
+        Predicate<CommandNode<?>> nodeFilter = node -> !(node instanceof ArgumentCommandNode<?, ?>) || argumentTypeFilter.test(((ArgumentCommandNode<?, ?>)node).getType());
+        return (RootCommandNode<S>)processCommandNode(root, nodeFilter, new HashMap<>());
+    }
+
+    private static <S> CommandNode<S> processCommandNode(CommandNode<S> node, Predicate<CommandNode<?>> nodeFilter, Map<CommandNode<S>, CommandNode<S>> newNodes)
+    {
+        CommandNode<S> existingNode = newNodes.get(node);
+        if (existingNode == null)
+        {
+            CommandNode<S> newNode = cloneNode(node, nodeFilter, newNodes);
+            newNodes.put(node, newNode);
+            node.getChildren().stream()
+                    .filter(nodeFilter)
+                    .map(child -> processCommandNode(child, nodeFilter, newNodes))
+                    .forEach(newNode::addChild);
+            return newNode;
+        }
+        else
+        {
+            return existingNode;
+        }
+    }
+
+    private static <S> CommandNode<S> cloneNode(CommandNode<S> node, Predicate<CommandNode<?>> nodeFilter, Map<CommandNode<S>, CommandNode<S>> newNodes)
+    {
+        if (node instanceof RootCommandNode<?>)
+        {
+            return new RootCommandNode<>();
+        }
+        else
+        {
+            ArgumentBuilder<S, ?> builder = node.createBuilder();
+            if (node.getRedirect() != null)
+            {
+                if (nodeFilter.test(node.getRedirect()))
+                {
+                    builder.forward(processCommandNode(node.getRedirect(), nodeFilter, newNodes), node.getRedirectModifier(), node.isFork());
+                }
+                else
+                {
+                    builder.redirect(null);
+                }
+            }
+            return builder.build();
+        }
+    }
+
+}

src/main/java/net/minecraftforge/network/VanillaConnectionNetworkFilter.java

@@ -0,0 +1,118 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.network;
+
+import java.util.AbstractMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import javax.annotation.Nonnull;
+
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToMessageEncoder;
+import net.minecraft.command.ISuggestionProvider;
+import net.minecraft.command.arguments.ArgumentTypes;
+import net.minecraft.network.IPacket;
+import net.minecraft.network.NetworkManager;
+import net.minecraft.network.play.server.SCommandListPacket;
+import net.minecraft.network.play.server.SEntityPropertiesPacket;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.fml.network.NetworkHooks;
+import net.minecraftforge.registries.ForgeRegistries;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import com.google.common.collect.ImmutableMap;
+import com.mojang.brigadier.tree.RootCommandNode;
+
+/**
+ * A filter for network packets, used to filter/modify parts of vanilla network messages that
+ * will cause errors or warnings on vanilla clients, for example entity attributes that are added by Forge or mods.
+ */
+public class VanillaConnectionNetworkFilter extends MessageToMessageEncoder<IPacket<?>>
+{
+
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    private static final Map<Class<? extends IPacket<?>>, Function<IPacket<?>, ? extends IPacket<?>>> handlers = ImmutableMap.<Class<? extends IPacket<?>>, Function<IPacket<?>, ? extends IPacket<?>>>builder()
+            .put(handler(SEntityPropertiesPacket.class, VanillaConnectionNetworkFilter::filterEntityProperties))
+            .put(handler(SCommandListPacket.class, VanillaConnectionNetworkFilter::filterCommandList))
+            .build();
+
+
+    public static void injectIfNecessary(NetworkManager manager)
+    {
+        if (NetworkHooks.isVanillaConnection(manager))
+        {
+            manager.channel().pipeline().addBefore("packet_handler", "forge:vanilla_filter", new VanillaConnectionNetworkFilter());
+            LOGGER.debug("Injected into {}", manager);
+        }
+    }
+
+    /**
+     * Helper function for building the handler map.
+     */
+    @Nonnull
+    private static <T extends IPacket<?>> Map.Entry<Class<? extends IPacket<?>>, Function<IPacket<?>, ? extends IPacket<?>>> handler(Class<T> cls, Function<T, ? extends IPacket<?>> function)
+    {
+        return new AbstractMap.SimpleEntry<>(cls, function.compose(cls::cast));
+    }
+
+    /**
+     * Filter for SEntityPropertiesPacket. Filters out any entity attributes that are not in the "minecraft" namespace.
+     * A vanilla client would ignore these with an error log.
+     */
+    @Nonnull
+    private static SEntityPropertiesPacket filterEntityProperties(SEntityPropertiesPacket msg)
+    {
+        SEntityPropertiesPacket newPacket = new SEntityPropertiesPacket();
+        msg.getSnapshots().stream()
+                .filter(snapshot -> {
+                    ResourceLocation key = ForgeRegistries.ATTRIBUTES.getKey(snapshot.func_240834_a_());
+                    return key != null && key.getNamespace().equals("minecraft");
+                })
+                .forEach(snapshot -> newPacket.getSnapshots().add(snapshot));
+        return newPacket;
+    }
+
+    /**
+     * Filter for SCommandListPacket. Uses {@link CommandTreeCleaner} to filter out any ArgumentTypes that are not in the "minecraft" or "brigadier" namespace.
+     * A vanilla client would fail to deserialize the packet and disconnect with an error message if these were sent.
+     */
+    @Nonnull
+    private static SCommandListPacket filterCommandList(SCommandListPacket packet)
+    {
+        RootCommandNode<ISuggestionProvider> root = packet.getRoot();
+        RootCommandNode<ISuggestionProvider> newRoot = CommandTreeCleaner.cleanArgumentTypes(root, argType -> {
+            ResourceLocation id = ArgumentTypes.getId(argType);
+            return id != null && (id.getNamespace().equals("minecraft") || id.getNamespace().equals("brigadier"));
+        });
+        return new SCommandListPacket(newRoot);
+    }
+
+    @Override
+    protected void encode(ChannelHandlerContext ctx, IPacket<?> msg, List<Object> out)
+    {
+        Function<IPacket<?>, ? extends IPacket<?>> function = handlers.getOrDefault(msg.getClass(), Function.identity());
+        out.add(function.apply(msg));
+    }
+}

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

@@ -680,6 +680,9 @@ public class GameData
 
                 for (ResourceLocation s : missingRegs)
                     text.append(s).append("\n");
+
+                LOGGER.warn(REGISTRIES, header);
+                LOGGER.warn(REGISTRIES, text.toString());
             }
         }
 
@@ -692,7 +695,7 @@ public class GameData
         {
             final Class<? extends IForgeRegistryEntry> clazz = RegistryManager.ACTIVE.getSuperType(key);
             remaps.put(key, Maps.newLinkedHashMap());
-            missing.put(key, Maps.newHashMap());
+            missing.put(key, Maps.newLinkedHashMap());
             loadPersistentDataToStagingRegistry(RegistryManager.ACTIVE, STAGING, remaps.get(key), missing.get(key), key, value, clazz);
         });
 
@@ -769,6 +772,9 @@ public class GameData
                     entries.stream().sorted((o1, o2) -> o1.compareNamespaced(o2)).forEach(rl -> buf.append("    ").append(rl).append("\n"));
                     buf.append("\n");
                 });
+
+                LOGGER.warn(REGISTRIES, header);
+                LOGGER.warn(REGISTRIES, buf.toString());
             }
 
             if (!defaulted.isEmpty())
@@ -861,7 +867,7 @@ public class GameData
     {
         ForgeRegistry<T> frozen = RegistryManager.FROZEN.getRegistry(name);
         ForgeRegistry<T> newRegistry = STAGING.getRegistry(name, RegistryManager.FROZEN);
-        Map<ResourceLocation, Integer> _new = Maps.newHashMap();
+        Map<ResourceLocation, Integer> _new = Maps.newLinkedHashMap();
         frozen.getKeys().stream().filter(key -> !newRegistry.containsKey(key)).forEach(key -> _new.put(key, frozen.getID(key)));
         newRegistry.loadIds(_new, frozen.getOverrideOwners(), Maps.newLinkedHashMap(), remaps, frozen, name);
     }

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

@@ -19,6 +19,7 @@
 
 package net.minecraftforge.server.command;
 
+import com.google.gson.JsonObject;
 import com.mojang.brigadier.StringReader;
 import com.mojang.brigadier.arguments.ArgumentType;
 import com.mojang.brigadier.context.CommandContext;
@@ -26,6 +27,9 @@ import com.mojang.brigadier.exceptions.CommandSyntaxException;
 import com.mojang.brigadier.suggestion.Suggestions;
 import com.mojang.brigadier.suggestion.SuggestionsBuilder;
 import net.minecraft.command.ISuggestionProvider;
+import net.minecraft.command.arguments.IArgumentSerializer;
+import net.minecraft.network.PacketBuffer;
+
 import java.util.Collection;
 import java.util.concurrent.CompletableFuture;
 import java.util.stream.Collectors;
@@ -56,28 +60,33 @@ public class EnumArgument<T extends Enum<T>> implements ArgumentType<T> {
         return Stream.of(enumClass.getEnumConstants()).map(Object::toString).collect(Collectors.toList());
     }
 
-    /* JAVAC HATES RAW TYPES!
-    @SuppressWarnings({"rawtypes", "unchecked"})
-    public static class Serialzier implements IArgumentSerializer<EnumArgument> {
+    public static class Serializer implements IArgumentSerializer<EnumArgument<?>>
+    {
         @Override
-        public void write(EnumArgument argument, PacketBuffer buffer) {
+        public void write(EnumArgument<?> argument, PacketBuffer buffer)
+        {
             buffer.writeString(argument.enumClass.getName());
         }
 
+        @SuppressWarnings({"unchecked", "rawtypes"})
         @Override
-        public EnumArgument<?> read(PacketBuffer buffer) {
-            try {
+        public EnumArgument<?> read(PacketBuffer buffer)
+        {
+            try
+            {
                 String name = buffer.readString();
                 return new EnumArgument(Class.forName(name));
-            } catch (ClassNotFoundException e) {
+            }
+            catch (ClassNotFoundException e)
+            {
                 return null;
             }
         }
 
         @Override
-        public void write(EnumArgument argument, JsonObject json) {
+        public void write(EnumArgument<?> argument, JsonObject json)
+        {
             json.addProperty("enum", argument.enumClass.getName());
         }
     }
-    */
 }

src/main/resources/META-INF/accesstransformer.cfg

@@ -318,7 +318,11 @@ public net.minecraft.world.chunk.ChunkStatus <init>(Ljava/lang/String;Lnet/minec
 private-f net.minecraft.world.gen.DebugChunkGenerator field_177462_b #GRID_WIDTH
 private-f net.minecraft.world.gen.DebugChunkGenerator field_177464_a #ALL_VALID_STATES
 private-f net.minecraft.world.gen.DebugChunkGenerator field_181039_c #GRID_HEIGHT
+public net.minecraft.world.gen.blockplacer.BlockPlacerType <init>(Lcom/mojang/serialization/Codec;)V # constructor
+public net.minecraft.world.gen.blockstateprovider.BlockStateProviderType <init>(Lcom/mojang/serialization/Codec;)V # constructor
+public net.minecraft.world.gen.foliageplacer.FoliagePlacerType <init>(Lcom/mojang/serialization/Codec;)V # constructor
 public net.minecraft.world.gen.layer.LayerUtil func_202829_a(JLnet/minecraft/world/gen/layer/traits/IAreaTransformer1;Lnet/minecraft/world/gen/area/IAreaFactory;ILjava/util/function/LongFunction;)Lnet/minecraft/world/gen/area/IAreaFactory; # repeat
+public net.minecraft.world.gen.treedecorator.TreeDecoratorType <init>(Lcom/mojang/serialization/Codec;)V # constructor
 private-f net.minecraft.world.raid.Raid$WaveMember field_221284_f # VALUES
 public net.minecraft.world.server.ServerChunkProvider field_186029_c # chunkGenerator
 public net.minecraft.world.server.ServerChunkProvider field_73251_h # worldObj

src/main/resources/forge.sas

@@ -27,6 +27,7 @@ net/minecraft/block/Block func_185473_a(Lnet/minecraft/world/IBlockReader;Lnet/m
 	net/minecraft/block/TallSeaGrassBlock func_185473_a(Lnet/minecraft/world/IBlockReader;Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/block/BlockState;)Lnet/minecraft/item/ItemStack;
 # Vanilla blocks calling these sided methods in getItem
 net/minecraft/tileentity/BannerTileEntity func_190615_l(Lnet/minecraft/block/BlockState;)Lnet/minecraft/item/ItemStack;
+net/minecraft/block/BannerBlock func_196287_a(Lnet/minecraft/item/DyeColor;)Lnet/minecraft/block/Block;
 net/minecraft/block/AttachedStemBlock func_196279_O_()Lnet/minecraft/item/Item;
 net/minecraft/block/StemBlock func_176481_j()Lnet/minecraft/item/Item;
 #=====================================
@@ -74,6 +75,8 @@ net/minecraft/item/crafting/IRecipe func_193358_e()Ljava/lang/String; # getGroup
 	net/minecraft/item/crafting/SingleItemRecipe func_193358_e()Ljava/lang/String;
 net/minecraft/nbt/CompressedStreamTools func_74797_a(Ljava/io/File;)Lnet/minecraft/nbt/CompoundNBT; # read
 net/minecraft/nbt/CompressedStreamTools func_74795_b(Lnet/minecraft/nbt/CompoundNBT;Ljava/io/File;)V # write
+net/minecraft/network/play/server/SCommandListPacket func_197693_a()Lcom/mojang/brigadier/tree/RootCommandNode; # getRoot
+net/minecraft/network/play/server/SEntityPropertiesPacket func_149441_d()Ljava/util/List; # getSnapshots
 net/minecraft/potion/Effect func_220303_e()Lnet/minecraft/potion/EffectType; # getEffectType
 net/minecraft/potion/Effect func_111186_k()Ljava/util/Map; # getAttributeModifierMap
 net/minecraft/potion/Effect func_188408_i()Z # isBeneficial

src/test/java/net/minecraftforge/debug/CodecsTest.java

@@ -0,0 +1,79 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2020.
+ *
+ * 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.debug;
+
+import net.minecraft.fluid.Fluids;
+import net.minecraft.nbt.CompoundNBT;
+import net.minecraft.nbt.NBTDynamicOps;
+import net.minecraftforge.fluids.FluidStack;
+import net.minecraftforge.fml.common.Mod;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+/**
+ * Created to host any custom codecs forge may be adding.
+ */
+@Mod("forge_codecs_test")
+public class CodecsTest
+{
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    public CodecsTest()
+    {
+        testFluidStackCodec();
+    }
+
+    /**
+     * Makes sure FluidStack.CODEC produces the same data as FluidStack.write
+     */
+    private void testFluidStackCodec()
+    {
+        FluidStack noTag = new FluidStack(Fluids.WATER, 10);
+        FluidStack withTag = new FluidStack(Fluids.LAVA, 10);
+        withTag.getOrCreateChildTag("test").putString("value", "This is a test");
+
+        CompoundNBT noTag_write = noTag.writeToNBT(new CompoundNBT());
+        CompoundNBT withTag_write = withTag.writeToNBT(new CompoundNBT());
+
+        CompoundNBT noTag_encode = (CompoundNBT)FluidStack.CODEC.encodeStart(NBTDynamicOps.INSTANCE, noTag).getOrThrow(false, error -> {
+            LOGGER.error("Error encoding noTag: {}", error);
+        });
+        CompoundNBT withTag_encode = (CompoundNBT)FluidStack.CODEC.encodeStart(NBTDynamicOps.INSTANCE, withTag).getOrThrow(false, error -> {
+            LOGGER.error("Error encoding withTag: {}", error);
+        });
+
+        if (!noTag_write.equals(noTag_encode))
+            throw new IllegalStateException("Encoded noTag does not match");
+        if (!withTag_write.equals(withTag_encode))
+            throw new IllegalStateException("Encoded withTag does not match");
+
+        FluidStack noTag_decode = FluidStack.CODEC.decode(NBTDynamicOps.INSTANCE, noTag_encode).getOrThrow(false, error -> {
+            LOGGER.error("Error decoding noTag: {}", error);
+        }).getFirst();
+        FluidStack withTag_decode = FluidStack.CODEC.decode(NBTDynamicOps.INSTANCE, withTag_encode).getOrThrow(false, error -> {
+            LOGGER.error("Error decoding withTag: {}", error);
+        }).getFirst();
+
+        if (!noTag.equals(noTag_decode))
+            throw new IllegalStateException("Decoded noTag does not match");
+        if (!withTag.equals(withTag_decode))
+            throw new IllegalStateException("Decoded withTag does not match");
+    }
+}

src/test/java/net/minecraftforge/debug/client/rendering/RenderLocalPlayerTest.java

@@ -0,0 +1,49 @@
+package net.minecraftforge.debug.client.rendering;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.item.Items;
+import net.minecraft.util.ActionResultType;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.event.entity.player.PlayerInteractEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+
+@Mod(RenderLocalPlayerTest.MODID)
+@Mod.EventBusSubscriber(value = Dist.CLIENT)
+public class RenderLocalPlayerTest
+{
+    public static final String MODID = "render_local_player_test";
+    static final boolean ENABLED = false;
+
+    @SubscribeEvent
+    public static void onItemRightClickEntity(final PlayerInteractEvent.EntityInteract event)
+    {
+        if (ENABLED && event.getItemStack().getItem() == Items.STICK)
+        {
+            Minecraft mc = Minecraft.getInstance();
+            if (mc.getRenderViewEntity() == mc.player)
+            {
+                mc.setRenderViewEntity(event.getTarget());
+
+                event.setCancellationResult(ActionResultType.SUCCESS);
+                event.setCanceled(true);
+            }
+        }
+    }
+
+    @SubscribeEvent
+    public static void onItemRightClick(final PlayerInteractEvent.RightClickItem event)
+    {
+        if (ENABLED && event.getItemStack().getItem() == Items.STICK)
+        {
+            Minecraft mc = Minecraft.getInstance();
+            if (mc.getRenderViewEntity() != mc.player)
+            {
+                mc.setRenderViewEntity(mc.player);
+
+                event.setCancellationResult(ActionResultType.SUCCESS);
+                event.setCanceled(true);
+            }
+        }
+    }
+}

src/test/resources/META-INF/mods.toml

@@ -92,3 +92,7 @@ license="LGPL v2.1"
     modId="player_game_mode_event_test"
 [[mods]]
     modId="structure_spawn_list_event_test"
+[[mods]]
+    modId="forge_codecs_test"
+[[mods]]
+    modId="render_local_player_test"