added ability set unmountable entities

src/main/java/carpet/mixins/Entity_scarpetEventsMixin.java

@@ -14,6 +14,8 @@ public abstract class Entity_scarpetEventsMixin implements EntityInterface
 {
     @Shadow public boolean removed;
 
+    private boolean permanentVehicle;
+
     private final EntityEventsGroup events = new EntityEventsGroup();
 
     @Override
@@ -22,6 +24,18 @@ public abstract class Entity_scarpetEventsMixin implements EntityInterface
         return events;
     }
 
+    @Override
+    public boolean isPermanentVehicle()
+    {
+        return permanentVehicle;
+    }
+
+    @Override
+    public void setPermanentVehicle(boolean permanent)
+    {
+        permanentVehicle = permanent;
+    }
+
     @Inject(method = "tick", at = @At("HEAD"))
     private void onTickCall(CallbackInfo ci)
     {
@@ -34,4 +48,6 @@ public abstract class Entity_scarpetEventsMixin implements EntityInterface
     {
         if (!removed) events.onEvent(EntityEventsGroup.EntityEventType.ON_REMOVED, (Entity) (Object) this);
     }
+
+
 }

src/main/java/carpet/mixins/ServerPlayerEntity_scarpetEventMixin.java

@@ -1,5 +1,6 @@
 package carpet.mixins;
 
+import carpet.fakes.EntityInterface;
 import com.mojang.authlib.GameProfile;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.item.ItemStack;
@@ -53,4 +54,14 @@ public abstract class ServerPlayerEntity_scarpetEventMixin extends PlayerEntity
     {
         STATISTICS.onPlayerStatistic((ServerPlayerEntity) (Object)this, stat, amount);
     }
+
+    @Redirect(method = "method_14218", at = @At(
+            value = "INVOKE",
+            target = "Lnet/minecraft/server/network/ServerPlayerEntity;setSneaking(Z)V"
+    ))
+    private void setSneakingConditionally(ServerPlayerEntity serverPlayerEntity, boolean sneaking)
+    {
+        if (!((EntityInterface)serverPlayerEntity.getVehicle()).isPermanentVehicle()) // won't since that method makes sure its not null
+            serverPlayerEntity.setSneaking(sneaking);
+    }
 }