Fixed broken players when a passenger disconnects whilst being carried

src/main/java/com/minelittlepony/unicopia/mixin/MixinPlayerManager.java

@@ -0,0 +1,37 @@
+package com.minelittlepony.unicopia.mixin;
+
+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;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.minelittlepony.unicopia.entity.player.Pony;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.server.PlayerManager;
+import net.minecraft.server.network.ServerPlayerEntity;
+
+@Mixin(PlayerManager.class)
+abstract class MixinPlayerManager {
+    @Inject(method = "remove", at = @At("HEAD"))
+    public void onRemove(ServerPlayerEntity player, CallbackInfo info) {
+        player.getPassengerList().stream()
+            .flatMap(passenger -> Pony.of(passenger).stream())
+            .forEach(passenger -> passenger.setCarrier((Entity)null));
+        player.removeAllPassengers();
+
+        @Nullable
+        Entity vehicle = null;
+        if (player.hasVehicle() && (vehicle = player.getRootVehicle()).hasPlayerRider()) {
+            if (vehicle.streamPassengersAndSelf().anyMatch(e -> {
+                return e != player && e instanceof PlayerEntity;
+            })) {
+                player.stopRiding();
+                Pony.of(player).setCarrier((Entity)null);
+            }
+        }
+    }
+
+}

src/main/resources/unicopia.mixin.json

@@ -28,6 +28,7 @@
     "MixinPersistentProjectileEntity",
     "MixinPlayerEntity",
     "MixinPlayerInventory",
+    "MixinPlayerManager",
     "MixinPowderSnowBlock",
     "MixinProjectileEntity",
     "MixinServerPlayerEntity",