blocks: set cave_air and void_air to null too

src/main/java/de/bixilon/minosoft/data/registries/blocks/BlockState.kt

@@ -125,7 +125,9 @@ data class BlockState(
             val outlineShape = data["outline_shape"]?.asShape() ?: VoxelShape.EMPTY
 
 
-            val lightProperties = if (outlineShape == VoxelShape.FULL) {
+            val lightProperties = if (outlineShape == VoxelShape.EMPTY) {
+                TransparentProperty
+            } else if (outlineShape == VoxelShape.FULL) {
                 if (data["is_opaque"]?.toBoolean() != false) SolidProperty else TransparentProperty
             } else {
                 DirectedProperty.of(outlineShape)

src/main/java/de/bixilon/minosoft/data/registries/blocks/DefaultBlockFactories.kt

@@ -49,6 +49,7 @@ import de.bixilon.minosoft.data.registries.blocks.types.water.SeagrassBlock
 import de.bixilon.minosoft.data.registries.factory.clazz.DefaultClassFactory
 
 object DefaultBlockFactories : DefaultClassFactory<BlockFactory<*>>(
+    AirBlock,
     FluidBlock,
     DoorBlock,
     LeverBlock,

src/main/java/de/bixilon/minosoft/data/registries/blocks/types/AirBlock.kt

@@ -0,0 +1,29 @@
+/*
+ * Minosoft
+ * Copyright (C) 2020-2022 Moritz Zwerger
+ *
+ * This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * This software is not affiliated with Mojang AB, the original developer of Minecraft.
+ */
+
+package de.bixilon.minosoft.data.registries.blocks.types
+
+import de.bixilon.minosoft.data.registries.ResourceLocation
+import de.bixilon.minosoft.data.registries.blocks.BlockFactory
+import de.bixilon.minosoft.data.registries.registries.Registries
+
+@Deprecated("Air is always null!")
+open class AirBlock(resourceLocation: ResourceLocation, registries: Registries, data: Map<String, Any>) : Block(resourceLocation, registries, data) {
+
+    companion object : BlockFactory<AirBlock> {
+
+        override fun build(resourceLocation: ResourceLocation, registries: Registries, data: Map<String, Any>): AirBlock {
+            return AirBlock(resourceLocation, registries, data)
+        }
+    }
+}

src/main/java/de/bixilon/minosoft/data/registries/registries/registry/BlockStateRegistry.kt

@@ -17,6 +17,7 @@ import de.bixilon.kutil.exception.Broken
 import de.bixilon.kutil.json.JsonObject
 import de.bixilon.minosoft.data.registries.ResourceLocation
 import de.bixilon.minosoft.data.registries.blocks.BlockState
+import de.bixilon.minosoft.data.registries.blocks.types.AirBlock
 import de.bixilon.minosoft.data.registries.registries.Registries
 import de.bixilon.minosoft.protocol.protocol.ProtocolDefinition
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap
@@ -72,7 +73,11 @@ class BlockStateRegistry(var flattened: Boolean) : AbstractRegistry<BlockState?>
         if (id == ProtocolDefinition.AIR_BLOCK_ID) {
             return null
         }
-        return forceGet(id)
+        val state = forceGet(id) ?: return null
+        if (state.block is AirBlock) {
+            return null
+        }
+        return state
     }
 
     override fun getId(value: BlockState?): Int {