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/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index bc3df01aab3e79be9c2836820e0eacc69ea6c1f4..487b0d5cd608e84a793eba5fdbd50a9f3d95c79b 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -399,4 +399,10 @@ public class PaperWorldConfig {
         this.armorStandTick = this.getBoolean("armor-stands-tick", this.armorStandTick);
         log("ArmorStand ticking is " + (this.armorStandTick ? "enabled" : "disabled") + " by default");
     }
+
+    public int waterOverLavaFlowSpeed;
+    private void waterOverLavaFlowSpeed() {
+        waterOverLavaFlowSpeed = getInt("water-over-lava-flow-speed", 5);
+        log("Water over lava flow speed: " + waterOverLavaFlowSpeed);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/BlockFluids.java b/src/main/java/net/minecraft/server/BlockFluids.java
index f00b403e1e12acbb8eb6ad55da219b257219a8f4..a28ac8b00b22a8c7afc2b64f9720a4e32b653e5f 100644
--- a/src/main/java/net/minecraft/server/BlockFluids.java
+++ b/src/main/java/net/minecraft/server/BlockFluids.java
@@ -76,11 +76,28 @@ public class BlockFluids extends Block implements IFluidSource {
     @Override
     public void onPlace(IBlockData iblockdata, World world, BlockPosition blockposition, IBlockData iblockdata1, boolean flag) {
         if (this.a(world, blockposition, iblockdata)) {
-            world.getFluidTickList().a(blockposition, iblockdata.getFluid().getType(), this.b.a((IWorldReader) world));
+            world.getFluidTickList().a(blockposition, iblockdata.getFluid().getType(), this.getFlowSpeed(world, blockposition)); // Paper
         }
 
     }
 
+    // Paper start - Get flow speed. Throttle if its water and flowing adjacent to lava
+    public int getFlowSpeed(World world, BlockPosition blockposition) {
+        if (this.material == Material.WATER) {
+            if (
+                world.getMaterialIfLoaded(blockposition.north(1)) == Material.LAVA ||
+                world.getMaterialIfLoaded(blockposition.south(1)) == Material.LAVA ||
+                world.getMaterialIfLoaded(blockposition.west(1)) == Material.LAVA ||
+                world.getMaterialIfLoaded(blockposition.east(1)) == Material.LAVA
+            ) {
+                return world.paperConfig.waterOverLavaFlowSpeed;
+            }
+        }
+        return this.b.a(world);
+    }
+    // Paper end
+
+
     @Override
     public IBlockData updateState(IBlockData iblockdata, EnumDirection enumdirection, IBlockData iblockdata1, GeneratorAccess generatoraccess, BlockPosition blockposition, BlockPosition blockposition1) {
         if (iblockdata.getFluid().isSource() || iblockdata1.getFluid().isSource()) {
@@ -93,7 +110,7 @@ public class BlockFluids extends Block implements IFluidSource {
     @Override
     public void doPhysics(IBlockData iblockdata, World world, BlockPosition blockposition, Block block, BlockPosition blockposition1, boolean flag) {
         if (this.a(world, blockposition, iblockdata)) {
-            world.getFluidTickList().a(blockposition, iblockdata.getFluid().getType(), this.b.a((IWorldReader) world));
+            world.getFluidTickList().a(blockposition, iblockdata.getFluid().getType(), this.getFlowSpeed(world, blockposition)); // Paper
         }
 
     }