Add missing important BlockStateListPopulator methods (#7952)

patches/server/0912-Add-missing-important-BlockStateListPopulator-method.patch

@@ -0,0 +1,39 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
+Date: Sun, 12 Jun 2022 13:25:52 -0400
+Subject: [PATCH] Add missing important BlockStateListPopulator methods
+
+Without these methods it causes exceptions due to these being used by certain feature generators.
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java b/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java
+index 8e6a71c1e8b53faa70b893c76f5bd25f96a5e142..03153abb425acf2d615acc386c91a6524aaa80bf 100644
+--- a/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java
++++ b/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java
+@@ -129,4 +129,27 @@ public class BlockStateListPopulator extends DummyGeneratorAccess {
+     public DimensionType dimensionType() {
+         return this.world.dimensionType();
+     }
++    // Paper start
++    @Override
++    public boolean isFluidAtPosition(BlockPos pos, Predicate<FluidState> state) {
++        return state.test(this.getFluidState(pos));
++    }
++
++    @Override
++    public <T extends BlockEntity> java.util.Optional<T> getBlockEntity(BlockPos pos, net.minecraft.world.level.block.entity.BlockEntityType<T> type) {
++        BlockEntity tileentity = this.getBlockEntity(pos);
++
++        return tileentity != null && tileentity.getType() == type ? (java.util.Optional<T>) java.util.Optional.of(tileentity) : java.util.Optional.empty();
++    }
++
++    @Override
++    public BlockPos getHeightmapPos(net.minecraft.world.level.levelgen.Heightmap.Types heightmap, BlockPos pos) {
++        return world.getHeightmapPos(heightmap, pos);
++    }
++
++    @Override
++    public net.minecraft.world.level.storage.LevelData getLevelData() {
++        return world.getLevelData();
++    }
++    // Paper end
+ }