Prevent chunk loading from Fluid Flowing

paper-server/patches/sources/net/minecraft/world/level/material/FlowingFluid.java.patch

@@ -31,24 +31,58 @@
                      this.spreadTo(world, blockposition1, iblockdata1, Direction.DOWN, fluid2);
                      if (this.sourceNeighborCount(world, fluidPos) >= 3) {
                          this.spreadToSides(world, fluidPos, fluidState, blockState);
-@@ -167,7 +184,16 @@
+@@ -167,8 +184,19 @@
                  Direction enumdirection = (Direction) entry.getKey();
                  FluidState fluid1 = (FluidState) entry.getValue();
                  BlockPos blockposition1 = pos.relative(enumdirection);
-+
++                final BlockState blockStateIfLoaded = world.getBlockStateIfLoaded(blockposition1); // Paper - Prevent chunk loading from fluid flowing
++                if (blockStateIfLoaded == null) continue; // Paper - Prevent chunk loading from fluid flowing
+ 
+-                this.spreadTo(world, blockposition1, world.getBlockState(blockposition1), enumdirection, fluid1);
 +                // CraftBukkit start
 +                org.bukkit.block.Block source = CraftBlock.at(world, pos);
 +                BlockFromToEvent event = new BlockFromToEvent(source, org.bukkit.craftbukkit.block.CraftBlock.notchToBlockFace(enumdirection));
 +                world.getCraftServer().getPluginManager().callEvent(event);
- 
++
 +                if (event.isCancelled()) {
 +                    continue;
 +                }
 +                // CraftBukkit end
-                 this.spreadTo(world, blockposition1, world.getBlockState(blockposition1), enumdirection, fluid1);
++                this.spreadTo(world, blockposition1, blockStateIfLoaded, enumdirection, fluid1); // Paper - Prevent chunk loading from fluid flowing
              }
  
-@@ -444,10 +470,24 @@
+         }
+@@ -183,7 +211,8 @@
+         while (iterator.hasNext()) {
+             Direction enumdirection = (Direction) iterator.next();
+             BlockPos.MutableBlockPos blockposition_mutableblockposition1 = blockposition_mutableblockposition.setWithOffset(pos, enumdirection);
+-            BlockState iblockdata1 = world.getBlockState(blockposition_mutableblockposition1);
++            BlockState iblockdata1 = world.getBlockStateIfLoaded(blockposition_mutableblockposition1); // Paper - Prevent chunk loading from fluid flowing
++            if (iblockdata1 == null) continue; // Paper - Prevent chunk loading from fluid flowing
+             FluidState fluid = iblockdata1.getFluidState();
+ 
+             if (fluid.getType().isSame(this) && FlowingFluid.canPassThroughWall(enumdirection, world, pos, state, blockposition_mutableblockposition1, iblockdata1)) {
+@@ -306,7 +335,8 @@
+ 
+             if (enumdirection1 != direction) {
+                 BlockPos blockposition1 = pos.relative(enumdirection1);
+-                BlockState iblockdata1 = spreadCache.getBlockState(blockposition1);
++                BlockState iblockdata1 = spreadCache.getBlockStateIfLoaded(blockposition1); // Paper - Prevent chunk loading from fluid flowing
++                if (iblockdata1 == null) continue; // Paper - Prevent chunk loading from fluid flowing
+                 FluidState fluid = iblockdata1.getFluidState();
+ 
+                 if (this.canPassThrough(world, this.getFlowing(), pos, state, enumdirection1, blockposition1, iblockdata1, fluid)) {
+@@ -372,7 +402,8 @@
+         while (iterator.hasNext()) {
+             Direction enumdirection = (Direction) iterator.next();
+             BlockPos blockposition1 = pos.relative(enumdirection);
+-            BlockState iblockdata1 = world.getBlockState(blockposition1);
++            BlockState iblockdata1 = world.getBlockStateIfLoaded(blockposition1); // Paper - Prevent chunk loading from fluid flowing
++            if (iblockdata1 == null) continue; // Paper - Prevent chunk loading from fluid flowing
+             FluidState fluid = iblockdata1.getFluidState();
+ 
+             if (this.canMaybePassThrough(world, pos, state, enumdirection, blockposition1, iblockdata1, fluid)) {
+@@ -444,10 +475,24 @@
              if (fluid1.isEmpty()) {
                  fluidState = fluid1;
                  blockState = Blocks.AIR.defaultBlockState();
@@ -73,3 +107,34 @@
                  world.setBlock(pos, blockState, 3);
                  world.scheduleTick(pos, fluid1.getType(), i);
              }
+@@ -524,12 +569,27 @@
+         public BlockState getBlockState(BlockPos pos) {
+             return this.getBlockState(pos, this.getCacheKey(pos));
+         }
++        // Paper start - Prevent chunk loading from fluid flowing
++        public @javax.annotation.Nullable BlockState getBlockStateIfLoaded(BlockPos pos) {
++            return this.getBlockState(pos, this.getCacheKey(pos), false);
++        }
++        // Paper end - Prevent chunk loading from fluid flowing
+ 
+         private BlockState getBlockState(BlockPos pos, short packed) {
+-            return (BlockState) this.stateCache.computeIfAbsent(packed, (short1) -> {
+-                return this.level.getBlockState(pos);
+-            });
++        // Paper start - Prevent chunk loading from fluid flowing
++            return getBlockState(pos, packed, true);
+         }
++        private @javax.annotation.Nullable BlockState getBlockState(BlockPos pos, short packed, boolean load) {
++            BlockState blockState = this.stateCache.get(packed);
++            if (blockState == null) {
++                blockState = load ? level.getBlockState(pos) : level.getBlockStateIfLoaded(pos);
++                if (blockState != null) {
++                    this.stateCache.put(packed, blockState);
++                }
++            }
++            return blockState;
++        // Paper end - Prevent chunk loading from fluid flowing
++        }
+ 
+         public boolean isHole(BlockPos pos) {
+             return this.holeCache.computeIfAbsent(this.getCacheKey(pos), (short0) -> {