From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Byteflux <byte@byteflux.net>
Date: Wed, 8 Aug 2018 16:33:21 -0600
Subject: [PATCH] Configurable speed for water flowing over lava


diff --git a/src/main/java/net/minecraft/world/level/block/LiquidBlock.java b/src/main/java/net/minecraft/world/level/block/LiquidBlock.java
index 3d8def659e017e3d525c7b40eacaf579a5ba3b5b..4a1830f85f47014da63e4584f411d13f0f0cd8b3 100644
--- a/src/main/java/net/minecraft/world/level/block/LiquidBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/LiquidBlock.java
@@ -108,11 +108,31 @@ public class LiquidBlock extends Block implements BucketPickup {
     @Override
     public void onPlace(BlockState state, Level world, BlockPos pos, BlockState oldState, boolean notify) {
         if (this.shouldSpreadLiquid(world, pos, state)) {
-            world.scheduleTick(pos, state.getFluidState().getType(), this.fluid.getTickDelay(world));
+            world.scheduleTick(pos, state.getFluidState().getType(), this.getFlowSpeed(world, pos)); // Paper
         }
 
     }
 
+    // Paper start - Get flow speed. Throttle if its water and flowing adjacent to lava
+    public int getFlowSpeed(Level world, BlockPos blockposition) {
+        if (net.minecraft.core.registries.BuiltInRegistries.FLUID.wrapAsHolder(this.fluid).is(FluidTags.WATER)) {
+            if (
+                isLava(world, blockposition.north(1)) ||
+                isLava(world, blockposition.south(1)) ||
+                isLava(world, blockposition.west(1)) ||
+                isLava(world, blockposition.east(1))
+            ) {
+                return world.paperConfig().environment.waterOverLavaFlowSpeed;
+            }
+        }
+        return this.fluid.getTickDelay(world);
+    }
+    private static boolean isLava(Level world, BlockPos blockPos) {
+        final FluidState fluidState = world.getFluidIfLoaded(blockPos);
+        return fluidState != null && fluidState.is(FluidTags.LAVA);
+    }
+    // Paper end
+
     @Override
     public BlockState updateShape(BlockState state, Direction direction, BlockState neighborState, LevelAccessor world, BlockPos pos, BlockPos neighborPos) {
         if (state.getFluidState().isSource() || neighborState.getFluidState().isSource()) {
@@ -125,7 +145,7 @@ public class LiquidBlock extends Block implements BucketPickup {
     @Override
     public void neighborChanged(BlockState state, Level world, BlockPos pos, Block sourceBlock, BlockPos sourcePos, boolean notify) {
         if (this.shouldSpreadLiquid(world, pos, state)) {
-            world.scheduleTick(pos, state.getFluidState().getType(), this.fluid.getTickDelay(world));
+            world.scheduleTick(pos, state.getFluidState().getType(), this.getFlowSpeed(world, pos)); // Paper
         }
 
     }