From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: William Blake Galbreath <Blake.Galbreath@GMail.com>
Date: Mon, 19 Oct 2020 15:14:01 -0500
Subject: [PATCH] Furnace uses lava from underneath


diff --git a/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java
index a9809c18233d82f910735e59363a49de488defcd..affa084b6bd4a6792d1c55719f88f3fb16627761 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/AbstractFurnaceBlockEntity.java
@@ -218,6 +218,21 @@ public abstract class AbstractFurnaceBlockEntity extends BaseContainerBlockEntit
         }
 
         ItemStack itemstack = (ItemStack) blockEntity.items.get(1);
+        // Purpur start
+        boolean usedLavaFromUnderneath = false;
+        if (world.purpurConfig.furnaceUseLavaFromUnderneath && !blockEntity.isLit() && itemstack.isEmpty() && !blockEntity.items.get(0).isEmpty() && world.getGameTime() % 20 == 0) {
+            BlockPos below = blockEntity.getBlockPos().below();
+            BlockState belowState = world.getBlockStateIfLoaded(below);
+            if (belowState != null && belowState.is(Blocks.LAVA)) {
+                net.minecraft.world.level.material.FluidState fluidState = belowState.getFluidState();
+                if (fluidState != null && fluidState.isSource()) {
+                    world.setBlock(below, Blocks.AIR.defaultBlockState(), 3);
+                    itemstack = Items.LAVA_BUCKET.getDefaultInstance();
+                    usedLavaFromUnderneath = true;
+                }
+            }
+        }
+        // Purpur end
         ItemStack itemstack1 = (ItemStack) blockEntity.items.get(0);
         boolean flag2 = !itemstack1.isEmpty();
         boolean flag3 = !itemstack.isEmpty();
@@ -303,6 +318,7 @@ public abstract class AbstractFurnaceBlockEntity extends BaseContainerBlockEntit
             setChanged(world, pos, state);
         }
 
+        if (usedLavaFromUnderneath) blockEntity.items.set(1, ItemStack.EMPTY); // Purpur
     }
 
     private static boolean canBurn(RegistryAccess dynamicRegistryManager, @Nullable RecipeHolder<? extends AbstractCookingRecipe> recipe, SingleRecipeInput input, NonNullList<ItemStack> inventory, int maxCount) {
diff --git a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
index 1060208faaa18020c5762a2eb4851f6148b5f215..fda9fcf681927334937d25706c9127fbbecd2ed5 100644
--- a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
+++ b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
@@ -365,6 +365,17 @@ public class PurpurWorldConfig {
         farmlandGetsMoistFromBelow = getBoolean("blocks.farmland.gets-moist-from-below", farmlandGetsMoistFromBelow);
     }
 
+    public boolean furnaceUseLavaFromUnderneath = false;
+    private void furnaceSettings() {
+        if (PurpurConfig.version < 17) {
+            furnaceUseLavaFromUnderneath = getBoolean("blocks.furnace.infinite-fuel", furnaceUseLavaFromUnderneath);
+            boolean oldValue = getBoolean("blocks.furnace.infinite-fuel", furnaceUseLavaFromUnderneath);
+            set("blocks.furnace.infinite-fuel", null);
+            set("blocks.furnace.use-lava-from-underneath", oldValue);
+        }
+        furnaceUseLavaFromUnderneath = getBoolean("blocks.furnace.use-lava-from-underneath", furnaceUseLavaFromUnderneath);
+    }
+
     public int lavaInfiniteRequiredSources = 2;
     public int lavaSpeedNether = 10;
     public int lavaSpeedNotNether = 30;