Fixed pony skin data not being reliably sent to servers

src/main/java/com/minelittlepony/api/events/Channel.java

@@ -8,7 +8,6 @@ import net.fabricmc.fabric.api.networking.v1.PacketByteBufs;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayConnectionEvents;
 import net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking;
 import net.fabricmc.loader.api.FabricLoader;
-import net.minecraft.client.MinecraftClient;
 import net.minecraft.util.Identifier;
 
 import org.apache.logging.log4j.LogManager;
@@ -29,7 +28,6 @@ public class Channel {
     public static void bootstrap() {
         ClientLoginConnectionEvents.INIT.register((handler, client) -> {
            registered = false;
-           LOGGER.info("Resetting registered flag");
         });
         ServerPlayConnectionEvents.JOIN.register((handler, sender, server) -> {
             LOGGER.info("Sending consent packet to " + handler.getPlayer().getName().getString());
@@ -38,12 +36,14 @@ public class Channel {
         });
 
         ClientPlayNetworking.registerGlobalReceiver(REQUEST_PONY_DATA, (client, handler, ignored, sender) -> {
+            registered = true;
             if (client.player != null) {
                 Pony pony = Pony.getManager().getPony(client.player);
-                registered = true;
                 LOGGER.info("Server has just consented");
 
                 sender.sendPacket(CLIENT_PONY_DATA, MsgPonyData.write(pony.metadata(), PacketByteBufs.create()));
+            } else {
+                LOGGER.info("Server has just consented but the client player was not set");
             }
         });
         ServerPlayNetworking.registerGlobalReceiver(CLIENT_PONY_DATA, (server, player, ignore, buffer, ignore2) -> {
@@ -54,20 +54,19 @@ public class Channel {
         });
     }
 
-    public static void broadcastPonyData(PonyData packet) {
+    public static boolean broadcastPonyData(PonyData packet) {
         if (FabricLoader.getInstance().getEnvironmentType() != EnvType.CLIENT) {
             throw new RuntimeException("Client packet send called by the server");
         }
 
         if (!registered) {
-            if (MinecraftClient.getInstance().isInSingleplayer() || MinecraftClient.getInstance().isIntegratedServerRunning()) {
+            LOGGER.info("Skipping network packet as the server has not consented");
-                LOGGER.info("Sending pony skin data over as we are either in single-player or lan");
+            return false;
-            } else {
+        } else {
-                LOGGER.info("Skipping network packet as the server has not consented");
+            LOGGER.info("Sending pony data to server for player");
-                return;
-            }
         }
 
         ClientPlayNetworking.send(CLIENT_PONY_DATA, MsgPonyData.write(packet, PacketByteBufs.create()));
+        return true;
     }
 }

src/main/java/com/minelittlepony/client/compat/hdskins/DummyPony.java

@@ -4,7 +4,6 @@ import net.minecraft.client.world.ClientWorld;
 
 import com.minelittlepony.api.model.PreviewModel;
 import com.minelittlepony.api.pony.*;
-import com.minelittlepony.client.render.EquineRenderManager;
 import com.minelittlepony.hdskins.client.gui.player.*;
 import com.minelittlepony.hdskins.client.gui.player.skins.PlayerSkins;
 
@@ -13,18 +12,13 @@ import java.util.UUID;
 /**
  * Dummy model used for the skin uploading screen.
  */
-class DummyPony extends DummyPlayer implements PreviewModel, PonyManager.ForcedPony, EquineRenderManager.RegistrationHandler {
+class DummyPony extends DummyPlayer implements PreviewModel, PonyManager.ForcedPony {
 
     public DummyPony(ClientWorld world, PlayerSkins<?> textures) {
         super(world, textures);
         setUuid(UUID.randomUUID()); // uuid must be random so animations aren't linked between the two previews
     }
 
-    @Override
-    public boolean shouldUpdateRegistration(Pony pony) {
-        return false;
-    }
-
     @Override
     public boolean forceSeapony() {
         return getTextures().getPosture().getActiveSkinType() == MineLPHDSkins.seaponySkinType;

src/main/java/com/minelittlepony/client/mixin/MixinClientPlayerEntity.java

@@ -9,7 +9,6 @@ import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityDimensions;
 import net.minecraft.entity.EntityPose;
 
-import org.jetbrains.annotations.Nullable;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
 import org.spongepowered.asm.mixin.injection.Inject;
@@ -20,8 +19,7 @@ import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 abstract class MixinClientPlayerEntity extends AbstractClientPlayerEntity implements EquineRenderManager.RegistrationHandler {
     public MixinClientPlayerEntity() { super(null, null); }
 
-    @Nullable
+    private final EquineRenderManager.SyncedPony syncedPony = new EquineRenderManager.SyncedPony();
-    private Pony pony;
 
     @Inject(method = "startRiding(Lnet/minecraft/entity/Entity;Z)Z", at = @At("RETURN"))
     private void onStartRiding(Entity entity, boolean bl, CallbackInfoReturnable<Boolean> info) {
@@ -34,12 +32,8 @@ abstract class MixinClientPlayerEntity extends AbstractClientPlayerEntity implem
     }
 
     @Override
-    public boolean shouldUpdateRegistration(Pony pony) {
+    public EquineRenderManager.SyncedPony getSyncedPony() {
-        if (this.pony != pony && (this.pony == null || this.pony.metadata().compareTo(pony.metadata()) != 0)) {
+        return syncedPony;
-            this.pony = pony.immutableCopy();
-            return true;
-        }
-        return false;
     }
 
     @Override

src/main/java/com/minelittlepony/client/render/EquineRenderManager.java

@@ -22,6 +22,8 @@ import net.minecraft.entity.Entity;
 import net.minecraft.entity.LivingEntity;
 import net.minecraft.entity.player.PlayerEntity;
 
+import org.jetbrains.annotations.Nullable;
+
 public class EquineRenderManager<T extends LivingEntity, M extends EntityModel<T> & PonyModel<T>> {
 
     private ModelWrapper<T, M> playerModel;
@@ -120,16 +122,31 @@ public class EquineRenderManager<T extends LivingEntity, M extends EntityModel<T
         Pony pony = renderer.getEntityPony(entity);
         playerModel.applyMetadata(pony.metadata());
 
-        if (pony.hasMetadata() && entity instanceof RegistrationHandler && ((RegistrationHandler)entity).shouldUpdateRegistration(pony)) {
+        if (entity instanceof PlayerEntity player && entity instanceof RegistrationHandler handler) {
-            entity.calculateDimensions();
+            SyncedPony synced = handler.getSyncedPony();
+            boolean changed = pony.compareTo(synced.lastRenderedPony) != 0;
 
-            PlayerEntity clientPlayer = MinecraftClient.getInstance().player;
+            if (changed) {
-            if (clientPlayer != null) {
+                synced.lastRenderedPony = pony;
-                if (Objects.equals(entity, clientPlayer) || Objects.equals(((PlayerEntity)entity).getGameProfile(), clientPlayer.getGameProfile())) {
+                player.calculateDimensions();
-                    Channel.broadcastPonyData(pony.metadata());
+            }
+
+            if (!(player instanceof PreviewModel)) {
+                @Nullable
+                PlayerEntity clientPlayer = MinecraftClient.getInstance().player;
+
+                if (pony.compareTo(synced.lastTransmittedPony) != 0) {
+                    if (clientPlayer != null && (Objects.equals(player, clientPlayer) || Objects.equals(player.getGameProfile(), clientPlayer.getGameProfile()))) {
+                        if (Channel.broadcastPonyData(pony.metadata())) {
+                            synced.lastTransmittedPony = pony;
+                        }
+                    }
+                }
+
+                if (changed) {
+                    PonyDataCallback.EVENT.invoker().onPonyDataAvailable(player, pony.metadata(), EnvType.CLIENT);
                 }
             }
-            PonyDataCallback.EVENT.invoker().onPonyDataAvailable((PlayerEntity)entity, pony.metadata(), EnvType.CLIENT);
         }
 
         getModel().updateLivingState(entity, pony, mode);
@@ -169,6 +186,13 @@ public class EquineRenderManager<T extends LivingEntity, M extends EntityModel<T
     }
 
     public interface RegistrationHandler {
-        boolean shouldUpdateRegistration(Pony pony);
+        SyncedPony getSyncedPony();
+    }
+
+    public static class SyncedPony {
+        @Nullable
+        private Pony lastRenderedPony;
+        @Nullable
+        private Pony lastTransmittedPony;
     }
 }