Add (untested) processing capability and second passes where appropriate

worldedit-bukkit/adapters/adapter-1_19_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/ext/fawe/v1_19_R3/PaperweightAdapter.java

@@ -780,12 +780,12 @@ public final class PaperweightAdapter implements BukkitImplAdapter<net.minecraft
     }
 
     private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
-            SideEffect.NEIGHBORS,
+            //FAWE start - FAWE-supported side effects
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
             SideEffect.LIGHTING,
-            SideEffect.VALIDATION,
+            SideEffect.NEIGHBORS
-            SideEffect.ENTITY_AI,
+            //FAWE end
-            SideEffect.EVENTS,
-            SideEffect.UPDATE
     );
 
     @Override

worldedit-bukkit/adapters/adapter-1_19_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R3/FaweMutableBlockPlaceContext.java

@@ -16,7 +16,11 @@ import javax.annotation.Nullable;
 
 public class FaweMutableBlockPlaceContext extends BlockPlaceContext {
 
-    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(Vec3.ZERO, Direction.NORTH, BlockPos.ZERO, false);
+    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(new Vec3(
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE
+    ), Direction.NORTH, BlockPos.ZERO, false);
     private final ServerLevel level;
     private BlockHitResult hitResult = null;
     private Direction direction = null;

worldedit-bukkit/adapters/adapter-1_19_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R3/PaperweightFaweAdapter.java

@@ -13,6 +13,7 @@ import com.fastasyncworldedit.core.util.NbtUtils;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Sets;
 import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
@@ -283,9 +284,16 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
         return state.toBaseBlock();
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
+            SideEffect.LIGHTING,
+            SideEffect.NEIGHBORS
+    );
+
     @Override
     public Set<SideEffect> getSupportedSideEffects() {
-        return SideEffectSet.defaults().getSideEffectsToApply();
+        return SUPPORTED_SIDE_EFFECTS;
     }
 
     @Override
@@ -606,8 +614,13 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
     }
 
     @Override
-    public PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    public PlacementStateProcessor getPlatformPlacementProcessor(
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
+        return new PaperweightPlacementStateProcessor(extent, mask, secondPass, includeUnedited);
     }
 
     private boolean wasAccessibleSinceLastSave(ChunkHolder holder) {

worldedit-bukkit/adapters/adapter-1_19_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R3/PaperweightPlacementStateProcessor.java

@@ -1,6 +1,7 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_19_R3;
 
 import com.fastasyncworldedit.core.extent.processor.PlacementStateProcessor;
+import com.fastasyncworldedit.core.math.IntTriple;
 import com.fastasyncworldedit.core.util.ExtentTraverser;
 import com.fastasyncworldedit.core.wrappers.WorldWrapper;
 import com.sk89q.worldedit.EditSession;
@@ -21,6 +22,7 @@ import net.minecraft.world.phys.Vec3;
 import org.bukkit.craftbukkit.v1_19_R3.CraftWorld;
 
 import javax.annotation.Nullable;
+import java.util.Queue;
 
 public class PaperweightPlacementStateProcessor extends PlacementStateProcessor {
 
@@ -28,13 +30,15 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
             .getInstance()
             .getBukkitImplAdapter());
     private final FaweMutableBlockPlaceContext mutableBlockPlaceContext;
+    private final PaperweightLevelProxy proxyLevel;
 
     public PaperweightPlacementStateProcessor(
             final Extent extent,
             final BlockTypeMask mask,
-            final boolean includeUnedited
+            boolean secondPass,
+            boolean includeUnedited
     ) {
-        super(extent, mask, includeUnedited);
+        super(extent, mask, secondPass, includeUnedited);
         World world;
         if (extent.isWorld()) {
             world = (World) extent;
@@ -53,8 +57,23 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
                 ((CraftWorld) bukkitWorld.getWorld()).getHandle(),
                 extent
         );
-        mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+        this.proxyLevel = PaperweightLevelProxy.getInstance(((CraftWorld) bukkitWorld.getWorld()).getHandle(),
-        proxyLevel.setEnabled(true);
+                extent
+        );
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+    }
+
+    private PaperweightPlacementStateProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited,
+            Queue<IntTriple> crossChunkSecondPasses,
+            PaperweightLevelProxy proxyLevel
+    ) {
+        super(extent, mask, secondPass, includeUnedited, crossChunkSecondPasses);
+        this.proxyLevel = proxyLevel;
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
     }
 
     @Override
@@ -85,12 +104,19 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
         if (child == getExtent()) {
             return this;
         }
-        return new PaperweightPlacementStateProcessor(child, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(child, mask, secondPass, includeUnedited);
     }
 
     @Override
     public PlacementStateProcessor fork() {
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(
+                extent,
+                mask,
+                secondPass,
+                includeUnedited,
+                crossChunkSecondPasses,
+                proxyLevel
+        );
     }
 
 }

worldedit-bukkit/adapters/adapter-1_20/src/main/java/com/sk89q/worldedit/bukkit/adapter/ext/fawe/v1_20_R1/PaperweightAdapter.java

@@ -831,12 +831,12 @@ public final class PaperweightAdapter implements BukkitImplAdapter<net.minecraft
     }
 
     private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
-            SideEffect.NEIGHBORS,
+            //FAWE start - FAWE-supported side effects
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
             SideEffect.LIGHTING,
-            SideEffect.VALIDATION,
+            SideEffect.NEIGHBORS
-            SideEffect.ENTITY_AI,
+            //FAWE end
-            SideEffect.EVENTS,
-            SideEffect.UPDATE
     );
 
     @Override

worldedit-bukkit/adapters/adapter-1_20/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R1/FaweMutableBlockPlaceContext.java

@@ -16,7 +16,11 @@ import javax.annotation.Nullable;
 
 public class FaweMutableBlockPlaceContext extends BlockPlaceContext {
 
-    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(Vec3.ZERO, Direction.NORTH, BlockPos.ZERO, false);
+    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(new Vec3(
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE
+    ), Direction.NORTH, BlockPos.ZERO, false);
     private final ServerLevel level;
     private BlockHitResult hitResult = null;
     private Direction direction = null;

worldedit-bukkit/adapters/adapter-1_20/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R1/PaperweightFaweAdapter.java

@@ -13,6 +13,7 @@ import com.fastasyncworldedit.core.util.NbtUtils;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Sets;
 import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
@@ -283,9 +284,16 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
         return state.toBaseBlock();
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
+            SideEffect.LIGHTING,
+            SideEffect.NEIGHBORS
+    );
+
     @Override
     public Set<SideEffect> getSupportedSideEffects() {
-        return SideEffectSet.defaults().getSideEffectsToApply();
+        return SUPPORTED_SIDE_EFFECTS;
     }
 
     @Override
@@ -606,8 +614,13 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
     }
 
     @Override
-    public PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    public PlacementStateProcessor getPlatformPlacementProcessor(
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
+        return new PaperweightPlacementStateProcessor(extent, mask, secondPass, includeUnedited);
     }
 
     private boolean wasAccessibleSinceLastSave(ChunkHolder holder) {

worldedit-bukkit/adapters/adapter-1_20/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R1/PaperweightPlacementStateProcessor.java

@@ -1,6 +1,7 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_20_R1;
 
 import com.fastasyncworldedit.core.extent.processor.PlacementStateProcessor;
+import com.fastasyncworldedit.core.math.IntTriple;
 import com.fastasyncworldedit.core.util.ExtentTraverser;
 import com.fastasyncworldedit.core.wrappers.WorldWrapper;
 import com.sk89q.worldedit.EditSession;
@@ -21,6 +22,7 @@ import net.minecraft.world.phys.Vec3;
 import org.bukkit.craftbukkit.v1_20_R1.CraftWorld;
 
 import javax.annotation.Nullable;
+import java.util.Queue;
 
 public class PaperweightPlacementStateProcessor extends PlacementStateProcessor {
 
@@ -28,13 +30,15 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
             .getInstance()
             .getBukkitImplAdapter());
     private final FaweMutableBlockPlaceContext mutableBlockPlaceContext;
+    private final PaperweightLevelProxy proxyLevel;
 
     public PaperweightPlacementStateProcessor(
             final Extent extent,
             final BlockTypeMask mask,
-            final boolean includeUnedited
+            boolean secondPass,
+            boolean includeUnedited
     ) {
-        super(extent, mask, includeUnedited);
+        super(extent, mask, secondPass, includeUnedited);
         World world;
         if (extent.isWorld()) {
             world = (World) extent;
@@ -53,8 +57,23 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
                 ((CraftWorld) bukkitWorld.getWorld()).getHandle(),
                 extent
         );
-        mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+        this.proxyLevel = PaperweightLevelProxy.getInstance(((CraftWorld) bukkitWorld.getWorld()).getHandle(),
-        proxyLevel.setEnabled(true);
+                extent
+        );
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+    }
+
+    private PaperweightPlacementStateProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited,
+            Queue<IntTriple> crossChunkSecondPasses,
+            PaperweightLevelProxy proxyLevel
+    ) {
+        super(extent, mask, secondPass, includeUnedited, crossChunkSecondPasses);
+        this.proxyLevel = proxyLevel;
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
     }
 
     @Override
@@ -85,12 +104,19 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
         if (child == getExtent()) {
             return this;
         }
-        return new PaperweightPlacementStateProcessor(child, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(child, mask, secondPass, includeUnedited);
     }
 
     @Override
     public PlacementStateProcessor fork() {
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(
+                extent,
+                mask,
+                secondPass,
+                includeUnedited,
+                crossChunkSecondPasses,
+                proxyLevel
+        );
     }
 
 }

worldedit-bukkit/adapters/adapter-1_20_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/ext/fawe/v1_20_R2/PaperweightAdapter.java

@@ -780,12 +780,12 @@ public final class PaperweightAdapter implements BukkitImplAdapter<net.minecraft
     }
 
     private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
-            SideEffect.NEIGHBORS,
+            //FAWE start - FAWE-supported side effects
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
             SideEffect.LIGHTING,
-            SideEffect.VALIDATION,
+            SideEffect.NEIGHBORS
-            SideEffect.ENTITY_AI,
+            //FAWE end
-            SideEffect.EVENTS,
-            SideEffect.UPDATE
     );
 
     @Override

worldedit-bukkit/adapters/adapter-1_20_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R2/FaweMutableBlockPlaceContext.java

@@ -16,7 +16,11 @@ import javax.annotation.Nullable;
 
 public class FaweMutableBlockPlaceContext extends BlockPlaceContext {
 
-    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(Vec3.ZERO, Direction.NORTH, BlockPos.ZERO, false);
+    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(new Vec3(
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE
+    ), Direction.NORTH, BlockPos.ZERO, false);
     private final ServerLevel level;
     private BlockHitResult hitResult = null;
     private Direction direction = null;

worldedit-bukkit/adapters/adapter-1_20_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R2/PaperweightFaweAdapter.java

@@ -13,6 +13,7 @@ import com.fastasyncworldedit.core.util.NbtUtils;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Sets;
 import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
@@ -286,9 +287,16 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
         return state.toBaseBlock();
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
+            SideEffect.LIGHTING,
+            SideEffect.NEIGHBORS
+    );
+
     @Override
     public Set<SideEffect> getSupportedSideEffects() {
-        return SideEffectSet.defaults().getSideEffectsToApply();
+        return SUPPORTED_SIDE_EFFECTS;
     }
 
     @Override
@@ -609,8 +617,13 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
     }
 
     @Override
-    public PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    public PlacementStateProcessor getPlatformPlacementProcessor(
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
+        return new PaperweightPlacementStateProcessor(extent, mask, secondPass, includeUnedited);
     }
 
     private boolean wasAccessibleSinceLastSave(ChunkHolder holder) {

worldedit-bukkit/adapters/adapter-1_20_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R2/PaperweightPlacementStateProcessor.java

@@ -1,6 +1,7 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_20_R2;
 
 import com.fastasyncworldedit.core.extent.processor.PlacementStateProcessor;
+import com.fastasyncworldedit.core.math.IntTriple;
 import com.fastasyncworldedit.core.util.ExtentTraverser;
 import com.fastasyncworldedit.core.wrappers.WorldWrapper;
 import com.sk89q.worldedit.EditSession;
@@ -21,6 +22,7 @@ import net.minecraft.world.phys.Vec3;
 import org.bukkit.craftbukkit.v1_20_R2.CraftWorld;
 
 import javax.annotation.Nullable;
+import java.util.Queue;
 
 public class PaperweightPlacementStateProcessor extends PlacementStateProcessor {
 
@@ -28,13 +30,15 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
             .getInstance()
             .getBukkitImplAdapter());
     private final FaweMutableBlockPlaceContext mutableBlockPlaceContext;
+    private final PaperweightLevelProxy proxyLevel;
 
     public PaperweightPlacementStateProcessor(
             final Extent extent,
             final BlockTypeMask mask,
-            final boolean includeUnedited
+            boolean secondPass,
+            boolean includeUnedited
     ) {
-        super(extent, mask, includeUnedited);
+        super(extent, mask, secondPass, includeUnedited);
         World world;
         if (extent.isWorld()) {
             world = (World) extent;
@@ -53,8 +57,23 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
                 ((CraftWorld) bukkitWorld.getWorld()).getHandle(),
                 extent
         );
-        mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+        this.proxyLevel = PaperweightLevelProxy.getInstance(((CraftWorld) bukkitWorld.getWorld()).getHandle(),
-        proxyLevel.setEnabled(true);
+                extent
+        );
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+    }
+
+    private PaperweightPlacementStateProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited,
+            Queue<IntTriple> crossChunkSecondPasses,
+            PaperweightLevelProxy proxyLevel
+    ) {
+        super(extent, mask, secondPass, includeUnedited, crossChunkSecondPasses);
+        this.proxyLevel = proxyLevel;
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
     }
 
     @Override
@@ -85,12 +104,19 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
         if (child == getExtent()) {
             return this;
         }
-        return new PaperweightPlacementStateProcessor(child, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(child, mask, secondPass, includeUnedited);
     }
 
     @Override
     public PlacementStateProcessor fork() {
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(
+                extent,
+                mask,
+                secondPass,
+                includeUnedited,
+                crossChunkSecondPasses,
+                proxyLevel
+        );
     }
 
 }

worldedit-bukkit/adapters/adapter-1_20_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/ext.fawe/v1_20_R3/PaperweightAdapter.java

@@ -780,12 +780,12 @@ public final class PaperweightAdapter implements BukkitImplAdapter<net.minecraft
     }
 
     private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
-            SideEffect.NEIGHBORS,
+            //FAWE start - FAWE-supported side effects
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
             SideEffect.LIGHTING,
-            SideEffect.VALIDATION,
+            SideEffect.NEIGHBORS
-            SideEffect.ENTITY_AI,
+            //FAWE end
-            SideEffect.EVENTS,
-            SideEffect.UPDATE
     );
 
     @Override

worldedit-bukkit/adapters/adapter-1_20_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R3/FaweMutableBlockPlaceContext.java

@@ -16,7 +16,11 @@ import javax.annotation.Nullable;
 
 public class FaweMutableBlockPlaceContext extends BlockPlaceContext {
 
-    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(Vec3.ZERO, Direction.NORTH, BlockPos.ZERO, false);
+    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(new Vec3(
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE
+    ), Direction.NORTH, BlockPos.ZERO, false);
     private final ServerLevel level;
     private BlockHitResult hitResult = null;
     private Direction direction = null;

worldedit-bukkit/adapters/adapter-1_20_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R3/PaperweightFaweAdapter.java

@@ -13,6 +13,7 @@ import com.fastasyncworldedit.core.util.NbtUtils;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Sets;
 import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.bukkit.BukkitAdapter;
@@ -285,9 +286,16 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
         return state.toBaseBlock();
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
+            SideEffect.LIGHTING,
+            SideEffect.NEIGHBORS
+    );
+
     @Override
     public Set<SideEffect> getSupportedSideEffects() {
-        return SideEffectSet.defaults().getSideEffectsToApply();
+        return SUPPORTED_SIDE_EFFECTS;
     }
 
     @Override
@@ -607,8 +615,13 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
     }
 
     @Override
-    public PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    public PlacementStateProcessor getPlatformPlacementProcessor(
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
+        return new PaperweightPlacementStateProcessor(extent, mask, secondPass, includeUnedited);
     }
 
     private boolean wasAccessibleSinceLastSave(ChunkHolder holder) {

worldedit-bukkit/adapters/adapter-1_20_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R3/PaperweightPlacementStateProcessor.java

@@ -1,6 +1,7 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_20_R3;
 
 import com.fastasyncworldedit.core.extent.processor.PlacementStateProcessor;
+import com.fastasyncworldedit.core.math.IntTriple;
 import com.fastasyncworldedit.core.util.ExtentTraverser;
 import com.fastasyncworldedit.core.wrappers.WorldWrapper;
 import com.sk89q.worldedit.EditSession;
@@ -21,6 +22,7 @@ import net.minecraft.world.phys.Vec3;
 import org.bukkit.craftbukkit.v1_20_R3.CraftWorld;
 
 import javax.annotation.Nullable;
+import java.util.Queue;
 
 public class PaperweightPlacementStateProcessor extends PlacementStateProcessor {
 
@@ -28,13 +30,15 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
             .getInstance()
             .getBukkitImplAdapter());
     private final FaweMutableBlockPlaceContext mutableBlockPlaceContext;
+    private final PaperweightLevelProxy proxyLevel;
 
     public PaperweightPlacementStateProcessor(
             final Extent extent,
             final BlockTypeMask mask,
-            final boolean includeUnedited
+            boolean secondPass,
+            boolean includeUnedited
     ) {
-        super(extent, mask, includeUnedited);
+        super(extent, mask, secondPass, includeUnedited);
         World world;
         if (extent.isWorld()) {
             world = (World) extent;
@@ -53,8 +57,23 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
                 ((CraftWorld) bukkitWorld.getWorld()).getHandle(),
                 extent
         );
-        mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+        this.proxyLevel = PaperweightLevelProxy.getInstance(((CraftWorld) bukkitWorld.getWorld()).getHandle(),
-        proxyLevel.setEnabled(true);
+                extent
+        );
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+    }
+
+    private PaperweightPlacementStateProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited,
+            Queue<IntTriple> crossChunkSecondPasses,
+            PaperweightLevelProxy proxyLevel
+    ) {
+        super(extent, mask, secondPass, includeUnedited, crossChunkSecondPasses);
+        this.proxyLevel = proxyLevel;
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
     }
 
     @Override
@@ -85,12 +104,19 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
         if (child == getExtent()) {
             return this;
         }
-        return new PaperweightPlacementStateProcessor(child, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(child, mask, secondPass, includeUnedited);
     }
 
     @Override
     public PlacementStateProcessor fork() {
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(
+                extent,
+                mask,
+                secondPass,
+                includeUnedited,
+                crossChunkSecondPasses,
+                proxyLevel
+        );
     }
 
 }

worldedit-bukkit/adapters/adapter-1_20_5/src/main/java/com/sk89q/worldedit/bukkit/adapter/ext.fawe/v1_20_R4/PaperweightAdapter.java

@@ -857,12 +857,12 @@ public final class PaperweightAdapter implements BukkitImplAdapter<net.minecraft
     }
 
     private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
-            SideEffect.NEIGHBORS,
+            //FAWE start - FAWE-supported side effects
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
             SideEffect.LIGHTING,
-            SideEffect.VALIDATION,
+            SideEffect.NEIGHBORS
-            SideEffect.ENTITY_AI,
+            //FAWE end
-            SideEffect.EVENTS,
-            SideEffect.UPDATE
     );
 
     @Override

worldedit-bukkit/adapters/adapter-1_20_5/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R4/FaweMutableBlockPlaceContext.java

@@ -16,7 +16,11 @@ import javax.annotation.Nullable;
 
 public class FaweMutableBlockPlaceContext extends BlockPlaceContext {
 
-    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(Vec3.ZERO, Direction.NORTH, BlockPos.ZERO, false);
+    private static final BlockHitResult DEFAULT_BLOCK_HIT = new BlockHitResult(new Vec3(
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE,
+            Integer.MAX_VALUE
+    ), Direction.NORTH, BlockPos.ZERO, false);
     private final ServerLevel level;
     private BlockHitResult hitResult = null;
     private Direction direction = null;

worldedit-bukkit/adapters/adapter-1_20_5/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R4/PaperweightFaweAdapter.java

@@ -13,6 +13,7 @@ import com.fastasyncworldedit.core.util.NbtUtils;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Sets;
 import com.mojang.serialization.Codec;
 import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.blocks.BaseItemStack;
@@ -35,7 +36,6 @@ import com.sk89q.worldedit.registry.state.IntegerProperty;
 import com.sk89q.worldedit.registry.state.Property;
 import com.sk89q.worldedit.util.Direction;
 import com.sk89q.worldedit.util.SideEffect;
-import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.concurrency.LazyReference;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.nbt.BinaryTag;
@@ -295,9 +295,16 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
         return state.toBaseBlock();
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.HISTORY,
+            SideEffect.HEIGHTMAPS,
+            SideEffect.LIGHTING,
+            SideEffect.NEIGHBORS
+    );
+
     @Override
     public Set<SideEffect> getSupportedSideEffects() {
-        return SideEffectSet.defaults().getSideEffectsToApply();
+        return SUPPORTED_SIDE_EFFECTS;
     }
 
     @Override
@@ -631,8 +638,13 @@ public final class PaperweightFaweAdapter extends FaweAdapter<net.minecraft.nbt.
     }
 
     @Override
-    public PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    public PlacementStateProcessor getPlatformPlacementProcessor(
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
+        return new PaperweightPlacementStateProcessor(extent, mask, secondPass, includeUnedited);
     }
 
     private boolean wasAccessibleSinceLastSave(ChunkHolder holder) {

worldedit-bukkit/adapters/adapter-1_20_5/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R4/PaperweightLevelProxy.java

@@ -22,7 +22,6 @@ public class PaperweightLevelProxy extends ServerLevel {
     private PaperweightFaweAdapter adapter;
     private Extent extent;
     private ServerLevel serverLevel;
-    private boolean enabled = false;
 
     @SuppressWarnings("DataFlowIssue")
     public PaperweightLevelProxy() {
@@ -47,14 +46,10 @@ public class PaperweightLevelProxy extends ServerLevel {
         return newLevel;
     }
 
-    public void setEnabled(boolean enabled) {
-        this.enabled = enabled;
-    }
-
     @Nullable
     @Override
     public BlockEntity getBlockEntity(@Nonnull BlockPos blockPos) {
-        if (!enabled) {
+        if (blockPos.getX() == Integer.MAX_VALUE) {
             return null;
         }
         BlockEntity tileEntity = this.serverLevel.getChunkAt(blockPos).getBlockEntity(blockPos);
@@ -77,7 +72,7 @@ public class PaperweightLevelProxy extends ServerLevel {
     @Override
     @Nonnull
     public BlockState getBlockState(@Nonnull BlockPos blockPos) {
-        if (!enabled) {
+        if (blockPos.getX() == Integer.MAX_VALUE) {
             return Blocks.AIR.defaultBlockState();
         }
         com.sk89q.worldedit.world.block.BlockState state = this.extent.getBlock(
@@ -92,7 +87,7 @@ public class PaperweightLevelProxy extends ServerLevel {
     @Override
     @Nonnull
     public FluidState getFluidState(@Nonnull BlockPos pos) {
-        if (!enabled) {
+        if (pos.getX() == Integer.MAX_VALUE) {
             return Fluids.EMPTY.defaultFluidState();
         }
         return getBlockState(pos).getFluidState();
@@ -101,7 +96,7 @@ public class PaperweightLevelProxy extends ServerLevel {
     @SuppressWarnings("unused")
     @Override
     public boolean isWaterAt(@Nonnull BlockPos pos) {
-        if (!enabled) {
+        if (pos.getX() == Integer.MAX_VALUE) {
             return false;
         }
         return getBlockState(pos).getFluidState().is(FluidTags.WATER);

worldedit-bukkit/adapters/adapter-1_20_5/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R4/PaperweightPlacementStateProcessor.java

@@ -1,6 +1,7 @@
 package com.sk89q.worldedit.bukkit.adapter.impl.fawe.v1_20_R4;
 
 import com.fastasyncworldedit.core.extent.processor.PlacementStateProcessor;
+import com.fastasyncworldedit.core.math.IntTriple;
 import com.fastasyncworldedit.core.util.ExtentTraverser;
 import com.fastasyncworldedit.core.wrappers.WorldWrapper;
 import com.sk89q.worldedit.EditSession;
@@ -21,20 +22,23 @@ import net.minecraft.world.phys.Vec3;
 import org.bukkit.craftbukkit.CraftWorld;
 
 import javax.annotation.Nullable;
+import java.util.Queue;
 
 public class PaperweightPlacementStateProcessor extends PlacementStateProcessor {
 
     private final PaperweightFaweAdapter adapter = ((PaperweightFaweAdapter) WorldEditPlugin
             .getInstance()
             .getBukkitImplAdapter());
+    private final PaperweightLevelProxy proxyLevel;
     private final FaweMutableBlockPlaceContext mutableBlockPlaceContext;
 
     public PaperweightPlacementStateProcessor(
-            final Extent extent,
+            Extent extent,
-            final BlockTypeMask mask,
+            BlockTypeMask mask,
-            final boolean includeUnedited
+            boolean secondPass,
+            boolean includeUnedited
     ) {
-        super(extent, mask, includeUnedited);
+        super(extent, mask, secondPass, includeUnedited);
         World world;
         if (extent.isWorld()) {
             world = (World) extent;
@@ -49,34 +53,38 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
         } else {
             bukkitWorld = (BukkitWorld) world;
         }
-        PaperweightLevelProxy proxyLevel = PaperweightLevelProxy.getInstance(
+        this.proxyLevel = PaperweightLevelProxy.getInstance(((CraftWorld) bukkitWorld.getWorld()).getHandle(),
-                ((CraftWorld) bukkitWorld.getWorld()).getHandle(),
                 extent
         );
-        mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
-        proxyLevel.setEnabled(true);
+    }
+
+    private PaperweightPlacementStateProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited,
+            Queue<IntTriple> crossChunkSecondPasses,
+            PaperweightLevelProxy proxyLevel
+    ) {
+        super(extent, mask, secondPass, includeUnedited, crossChunkSecondPasses);
+        this.proxyLevel = proxyLevel;
+        this.mutableBlockPlaceContext = new FaweMutableBlockPlaceContext(proxyLevel);
     }
 
     @Override
     protected char getStateAtFor(
-            int x,
+            int x, int y, int z, BlockState state, Vector3 clickPos, Direction clickedFaceDirection, BlockVector3 clickedBlock
-            int y,
-            int z,
-            BlockState state,
-            Vector3 clickPos,
-            Direction clickedFaceDirection,
-            BlockVector3 clickedBlock
     ) {
         Block block = ((PaperweightBlockMaterial) state.getMaterial()).getBlock();
         Vec3 pos = new Vec3(clickPos.x(), clickPos.y(), clickPos.z());
         net.minecraft.core.Direction side = net.minecraft.core.Direction.valueOf(clickedFaceDirection.toString());
         BlockPos blockPos = new BlockPos(clickedBlock.x(), clickedBlock.y(), clickedBlock.z());
-        net.minecraft.world.level.block.state.BlockState newState = block.getStateForPlacement(mutableBlockPlaceContext.withSetting(
+        net.minecraft.world.level.block.state.BlockState newState = block.getStateForPlacement(mutableBlockPlaceContext.withSetting(new BlockHitResult(pos, side, blockPos, false),
-                new BlockHitResult(pos, side, blockPos, false),
                 side.getOpposite()
         ));
-        return newState == null ? BlockTypesCache.ReservedIDs.AIR :
+        return newState == null ? BlockTypesCache.ReservedIDs.AIR : adapter.ibdIDToOrdinal(Block.BLOCK_STATE_REGISTRY.getId(
-                adapter.ibdIDToOrdinal(Block.BLOCK_STATE_REGISTRY.getId(newState));
+                newState));
     }
 
     @Override
@@ -85,12 +93,19 @@ public class PaperweightPlacementStateProcessor extends PlacementStateProcessor
         if (child == getExtent()) {
             return this;
         }
-        return new PaperweightPlacementStateProcessor(child, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(child, mask, secondPass, includeUnedited);
     }
 
     @Override
     public PlacementStateProcessor fork() {
-        return new PaperweightPlacementStateProcessor(extent, mask, includeUnedited);
+        return new PaperweightPlacementStateProcessor(
+                extent,
+                mask,
+                secondPass,
+                includeUnedited,
+                crossChunkSecondPasses,
+                proxyLevel
+        );
     }
 
 }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitServerInterface.java

@@ -314,8 +314,13 @@ public class BukkitServerInterface extends AbstractPlatform implements MultiUser
     }
 
     @Override
-    public PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    public PlacementStateProcessor getPlatformPlacementProcessor(
-        return this.plugin.getBukkitImplAdapter().getPlatformPlacementProcessor(extent, mask, includeUnedited);
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
+        return this.plugin.getBukkitImplAdapter().getPlatformPlacementProcessor(extent, mask, secondPass, includeUnedited);
     }
     //FAWE end
 }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/BukkitImplAdapter.java

@@ -368,7 +368,12 @@ public interface BukkitImplAdapter<T> extends IBukkitAdapter {
      * Returns an {@link PlacementStateProcessor} instance for processing placed blocks to "fix" them.
      * @since TODO
      */
-    default PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    default PlacementStateProcessor getPlatformPlacementProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
         return null;
     }
     //FAWE end

worldedit-core/src/main/java/com/fastasyncworldedit/core/configuration/Settings.java

@@ -784,6 +784,11 @@ public class Settings extends Config {
         })
         public boolean UNSTUCK_ON_GENERATE = true;
 
+        @Comment({
+                "If edits that have a block update processor applied should also perform a second pass",
+        })
+        public boolean PERFORM_SECOND_UPDATE_PASS = true;
+
     }
 
 }

worldedit-core/src/main/java/com/fastasyncworldedit/core/extent/processor/PlacementStateProcessor.java

@@ -1,9 +1,10 @@
 package com.fastasyncworldedit.core.extent.processor;
 
 import com.fastasyncworldedit.core.extent.filter.block.FilterBlock;
+import com.fastasyncworldedit.core.math.IntPair;
+import com.fastasyncworldedit.core.math.IntTriple;
 import com.fastasyncworldedit.core.math.MutableBlockVector3;
 import com.fastasyncworldedit.core.math.MutableVector3;
-import com.fastasyncworldedit.core.queue.Filter;
 import com.fastasyncworldedit.core.queue.IBatchProcessor;
 import com.fastasyncworldedit.core.queue.IChunk;
 import com.fastasyncworldedit.core.queue.IChunkGet;
@@ -27,23 +28,39 @@ import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockTypes;
 import com.sk89q.worldedit.world.block.BlockTypesCache;
 
+import java.util.ArrayDeque;
 import java.util.EnumSet;
+import java.util.Queue;
 import java.util.Set;
+import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.stream.Collectors;
 
-public abstract class PlacementStateProcessor extends AbstractDelegateExtent implements IBatchProcessor, Filter, Pattern {
+public abstract class PlacementStateProcessor extends AbstractDelegateExtent implements IBatchProcessor, Pattern {
 
     private static final Direction[] NESW = new Direction[]{Direction.NORTH, Direction.EAST, Direction.SOUTH, Direction.WEST};
     private static volatile boolean SETUP = false;
     private static BlockTypeMask DEFAULT_MASK = null;
+    private static BlockTypeMask SECOND_MASK = null;
+    private static BlockTypeMask REQUIRES_SECOND_PASS = null;
 
     protected final Extent extent;
     protected final BlockTypeMask mask;
     protected final boolean includeUnedited;
+    protected final boolean secondPass;
+    protected final Queue<IntTriple> crossChunkSecondPasses;
     private final MutableVector3 clickPos = new MutableVector3();
     private final MutableBlockVector3 clickedBlock = new MutableBlockVector3();
 
-    public PlacementStateProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    /**
+     * Process/extent/pattern for performing block updates, e.g. stair shape and glass pane connections
+     *
+     * @param extent          Extent to use
+     * @param mask            Mask of blocks to perform updates on
+     * @param secondPass      Perform a second pass typically around stairs. May perform cross-chunk second passes too
+     * @param includeUnedited if unedited blocks should be processed as well
+     * @since TODO
+     */
+    public PlacementStateProcessor(Extent extent, BlockTypeMask mask, boolean secondPass, boolean includeUnedited) {
         super(extent);
         // Required here as child classes are located within adapters and will therefore be statically accessed on startup,
         // meaning we attempt to access BlockTypes class before it is correctly initialised.
@@ -56,12 +73,29 @@ public abstract class PlacementStateProcessor extends AbstractDelegateExtent imp
         }
         this.extent = extent;
         this.mask = mask == null ? DEFAULT_MASK : mask;
+        this.secondPass = secondPass;
         this.includeUnedited = includeUnedited;
+        this.crossChunkSecondPasses = secondPass ? null : new ConcurrentLinkedQueue<>();
+    }
+
+    protected PlacementStateProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited,
+            Queue<IntTriple> crossChunkSecondPasses
+    ) {
+        super(extent);
+        this.extent = extent;
+        this.mask = mask;
+        this.secondPass = secondPass;
+        this.includeUnedited = includeUnedited;
+        this.crossChunkSecondPasses = crossChunkSecondPasses;
     }
 
     private static void setup() {
-        DEFAULT_MASK = new BlockTypeMask(new NullExtent());
+        REQUIRES_SECOND_PASS = new BlockTypeMask(new NullExtent());
-        DEFAULT_MASK.add(
+        REQUIRES_SECOND_PASS.add(
                 BlockTypes.IRON_BARS,
                 BlockTypes.GLASS_PANE,
                 BlockTypes.BLACK_STAINED_GLASS_PANE,
@@ -80,6 +114,27 @@ public abstract class PlacementStateProcessor extends AbstractDelegateExtent imp
                 BlockTypes.ORANGE_STAINED_GLASS_PANE,
                 BlockTypes.RED_STAINED_GLASS_PANE,
                 BlockTypes.WHITE_STAINED_GLASS_PANE,
+                BlockTypes.TRIPWIRE,
+                BlockTypes.TWISTING_VINES_PLANT,
+                BlockTypes.CAVE_VINES_PLANT,
+                BlockTypes.WEEPING_VINES_PLANT,
+                BlockTypes.VINE,
+                BlockTypes.REDSTONE_WIRE
+        );
+        BlockCategory[] categories = new BlockCategory[]{
+                BlockCategories.FENCES,
+                BlockCategories.FENCE_GATES,
+                BlockCategories.WALLS,
+                BlockCategories.CAVE_VINES
+        };
+        for (BlockCategory category : categories) {
+            if (category != null) {
+                REQUIRES_SECOND_PASS.add(category.getAll());
+            }
+        }
+
+        DEFAULT_MASK = REQUIRES_SECOND_PASS.copy();
+        DEFAULT_MASK.add(
                 BlockTypes.CHORUS_PLANT,
                 BlockTypes.DRIPSTONE_BLOCK,
                 BlockTypes.POINTED_DRIPSTONE,
@@ -91,20 +146,20 @@ public abstract class PlacementStateProcessor extends AbstractDelegateExtent imp
                 BlockTypes.CRAFTER,
                 BlockTypes.MUSHROOM_STEM,
                 BlockTypes.BROWN_MUSHROOM_BLOCK,
-                BlockTypes.RED_MUSHROOM_BLOCK,
+                BlockTypes.RED_MUSHROOM_BLOCK
-                BlockTypes.TRIPWIRE,
-                BlockTypes.TWISTING_VINES_PLANT,
-                BlockTypes.CAVE_VINES_PLANT,
-                BlockTypes.WEEPING_VINES_PLANT,
-                BlockTypes.VINE,
-                BlockTypes.REDSTONE_WIRE
         );
-        BlockCategory[] categories = new BlockCategory[]{BlockCategories.FENCES, BlockCategories.FENCE_GATES, BlockCategories.STAIRS, BlockCategories.WALLS, BlockCategories.BAMBOO_BLOCKS, BlockCategories.CAVE_VINES, BlockCategories.TALL_FLOWERS};
+        categories = new BlockCategory[]{
+                BlockCategories.STAIRS,
+                BlockCategories.BAMBOO_BLOCKS,
+                BlockCategories.TALL_FLOWERS
+        };
         for (BlockCategory category : categories) {
             if (category != null) {
                 DEFAULT_MASK.add(category.getAll());
             }
         }
+        SECOND_MASK = new BlockTypeMask(new NullExtent());
+        SECOND_MASK.add(BlockCategories.STAIRS.getAll());
         SETUP = true;
     }
 
@@ -121,57 +176,128 @@ public abstract class PlacementStateProcessor extends AbstractDelegateExtent imp
                     continue;
                 }
             }
+            Queue<IntPair> secondPasses = this.secondPass ? new ArrayDeque<>() : null;
             for (int y = 0, i = 0; y < 16; y++) {
                 int blockY = layerY + y;
+                // Perform second pass to ensure changes to stairs are propagated to fences, walls, etc.
+                // Always perform if within chunk boundaries as this is not very costly.
+                // Only perform outside chunk boundaries if secondPass is not null
                 for (int z = 0; z < 16; z++) {
                     int blockZ = chunkZ + z;
                     for (int x = 0; x < 16; x++, i++) {
                         int blockX = chunkX + x;
-                        char ordinal = set == null ? BlockTypesCache.ReservedIDs.__RESERVED__ : set[i];
+                        checkAndPerformUpdate(iChunkGet, iChunkSet, get, set, layer, i, blockX, blockY, blockZ, x, z, secondPasses);
-                        if (ordinal == BlockTypesCache.ReservedIDs.__RESERVED__) {
+                    }
-                            if (!includeUnedited) {
+                }
+                if (!secondPass || secondPasses.isEmpty()) {
                     continue;
                 }
-                            if (get == null) {
+                IntPair pair;
-                                get = iChunkGet.load(layer);
+                while ((pair = secondPasses.poll()) != null) {
-                            }
+                    int x = pair.x();
-                            ordinal = get[i];
+                    int z = pair.z();
-                        }
+                    int blockX = chunkX + x;
-                        BlockState state = BlockTypesCache.states[ordinal];
+                    int blockZ = chunkZ + z;
-                        if (!mask.test(state.getBlockType())) {
+                    if (x < 0 || x > 15 || z < 0 || z > 15) {
-                            continue;
+                        crossChunkSecondPasses.add(new IntTriple(blockX, blockY, blockZ));
-                        }
-                        char newOrdinal = getBlockOrdinal(blockX, blockY, blockZ, state);
-                        if (set == null) {
-                            set = iChunkSet.load(layer);
-                        }
-                        set[i] = newOrdinal;
                     }
+                    int index = (y & 15) << 8 | z << 4 | x;
+                    checkAndPerformUpdate(iChunkGet, iChunkSet, get, set, layer, index, blockX, blockY, blockZ, x, z, null);
                 }
             }
         }
         return iChunkSet;
     }
 
+    private void checkAndPerformUpdate(
+            IChunkGet iChunkGet,
+            IChunkSet iChunkSet,
+            char[] get,
+            char[] set,
+            int layer,
+            int index,
+            int blockX,
+            int blockY,
+            int blockZ,
+            int x,
+            int z,
+            Queue<IntPair> secondPasses
+    ) {
+        char ordinal = set == null ? BlockTypesCache.ReservedIDs.__RESERVED__ : set[index];
+        if (ordinal == BlockTypesCache.ReservedIDs.__RESERVED__) {
+            if (!includeUnedited) {
+                return;
+            }
+            if (get == null) {
+                get = iChunkGet.load(layer);
+            }
+            ordinal = get[index];
+        }
+        BlockState state = BlockTypesCache.states[ordinal];
+        if (secondPasses == null && secondPass) {
+            if (!REQUIRES_SECOND_PASS.test(state.getBlockType())) {
+                return;
+            }
+        }
+        if (!mask.test(state.getBlockType())) {
+            return;
+        }
+        char newOrdinal = getBlockOrdinal(blockX, blockY, blockZ, state);
+        if (newOrdinal == ordinal) {
+            return;
+        }
+        if (secondPasses != null && (BlockCategories.STAIRS.contains(state) || secondPass && SECOND_MASK.test(state.getBlockType()))) {
+            secondPasses.add(new IntPair(x - 1, z));
+            secondPasses.add(new IntPair(x + 1, z));
+            secondPasses.add(new IntPair(x, z - 1));
+            secondPasses.add(new IntPair(x, z + 1));
+        }
+        if (set == null) {
+            set = iChunkSet.load(layer);
+        }
+        set[index] = newOrdinal;
+    }
+
     @Override
     public ProcessorScope getScope() {
         return ProcessorScope.CHANGING_BLOCKS;
     }
 
+    @Override
+    public void flush() {
+        IntTriple coords;
+        while ((coords = crossChunkSecondPasses.poll()) != null) {
+            BlockState state = extent.getBlock(coords.x(), coords.y(), coords.z());
+            char ordinal = state.getOrdinalChar();
+            if (ordinal == BlockTypesCache.ReservedIDs.__RESERVED__) {
+                continue;
+            }
+            if (!mask.test(state.getBlockType())) {
+                continue;
+            }
+            char newOrdinal = getBlockOrdinal(coords.x(), coords.y(), coords.z(), state);
+            if (newOrdinal == ordinal) {
+                continue;
+            }
+            extent.setBlock(coords.x(), coords.y(), coords.z(), BlockTypesCache.states[newOrdinal]);
+        }
+    }
+
     @Override
     public abstract PlacementStateProcessor fork();
 
     // Require block type to avoid duplicate lookup
     protected abstract char getStateAtFor(
-            int x, int y, int z, BlockState state, Vector3 clickPos, Direction clickedFaceDirection, BlockVector3 clickedBlock
+            int x,
+            int y,
+            int z,
+            BlockState state,
+            Vector3 clickPos,
+            Direction clickedFaceDirection,
+            BlockVector3 clickedBlock
     );
 
-    private char getBlockOrdinal(
+    private char getBlockOrdinal(final int blockX, final int blockY, final int blockZ, final BlockState state) {
-            final int blockX,
-            final int blockY,
-            final int blockZ,
-            final BlockState state
-    ) {
         EnumSet<Direction> dirs = Direction.getDirections(state);
         Direction clickedFaceDirection = null; // This should be always be set by the below.
         Set<String> states = state.getStates().keySet().stream().map(Property::getName).collect(Collectors.toSet());

worldedit-core/src/main/java/com/fastasyncworldedit/core/queue/IBatchProcessor.java

@@ -10,13 +10,14 @@ import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.world.block.BlockTypesCache;
 
 import javax.annotation.Nullable;
+import java.io.Flushable;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
 import java.util.function.Function;
 
-public interface IBatchProcessor {
+public interface IBatchProcessor extends Flushable {
 
     /**
      * Process a chunk that has been set.

worldedit-core/src/main/java/com/fastasyncworldedit/core/queue/implementation/ParallelQueueExtent.java

@@ -37,6 +37,7 @@ import com.sk89q.worldedit.world.block.BlockStateHolder;
 import com.sk89q.worldedit.world.block.BlockType;
 import org.apache.logging.log4j.Logger;
 
+import java.io.Flushable;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
@@ -135,7 +136,7 @@ public class ParallelQueueExtent extends PassthroughExtent {
             // if PQE is ever used with PARALLEL_THREADS = 1, or only one chunk is edited, just run sequentially
             while (chunksIter.hasNext()) {
                 BlockVector2 pos = chunksIter.next();
-                getExtent().apply(null, filter, region, pos.getX(), pos.getZ(), full);
+                getExtent().apply(null, filter, region, pos.x(), pos.z(), full);
             }
         } else {
             final ForkJoinTask[] tasks = IntStream.range(0, size).mapToObj(i -> handler.submit(() -> {
@@ -159,11 +160,14 @@ public class ParallelQueueExtent extends PassthroughExtent {
                                         break;
                                     }
                                     final BlockVector2 pos = chunksIter.next();
-                                    chunkX = pos.getX();
+                                    chunkX = pos.x();
-                                    chunkZ = pos.getZ();
+                                    chunkZ = pos.z();
                                 }
                                 block = queue.apply(block, newFilter, region, chunkX, chunkZ, full);
                             }
+                            if (newFilter instanceof Flushable flushable) {
+                                flushable.flush();
+                            }
                             queue.flush();
                         } catch (Throwable t) {
                             if (t instanceof FaweException) {

worldedit-core/src/main/java/com/sk89q/worldedit/EditSessionBuilder.java

@@ -65,6 +65,8 @@ import com.sk89q.worldedit.extent.inventory.BlockBag;
 import com.sk89q.worldedit.internal.util.LogManagerCompat;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.util.Identifiable;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.eventbus.EventBus;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
@@ -104,6 +106,7 @@ public final class EditSessionBuilder {
     private Extent extent;
     private boolean compiled;
     private boolean wrapped;
+    private SideEffectSet sideEffectSet = SideEffectSet.defaults();
 
     private @Nullable
     World world;
@@ -415,6 +418,14 @@ public final class EditSessionBuilder {
         return setDirty();
     }
 
+    /**
+     * Set the side effects to be used with this edit
+     */
+    public EditSessionBuilder setSideEffectSet(@Nullable SideEffectSet sideEffectSet) {
+        this.sideEffectSet = sideEffectSet;
+        return setDirty();
+    }
+
     /**
      * Compile the builder to the settings given. Prepares history, limits, lighting, etc.
      */
@@ -445,6 +456,9 @@ public final class EditSessionBuilder {
                 fastMode = actor.getSession().hasFastMode();
             }
         }
+        if (fastMode) {
+            sideEffectSet = SideEffectSet.none();
+        }
         if (checkMemory == null) {
             checkMemory = actor != null && !this.fastMode;
         }
@@ -491,7 +505,7 @@ public final class EditSessionBuilder {
             }
             extent = this.bypassAll = wrapExtent(extent, eventBus, event, EditSession.Stage.BEFORE_CHANGE);
             this.bypassHistory = this.extent = wrapExtent(bypassAll, eventBus, event, EditSession.Stage.BEFORE_REORDER);
-            if (!this.fastMode || changeSet != null) {
+            if (!this.fastMode  || this.sideEffectSet.shouldApply(SideEffect.HISTORY) || changeSet != null) {
                 if (changeSet == null) {
                     if (Settings.settings().HISTORY.USE_DISK) {
                         UUID uuid = actor == null ? Identifiable.CONSOLE : actor.getUniqueId();
@@ -546,13 +560,31 @@ public final class EditSessionBuilder {
             }
             // There's no need to do the below (and it'll also just be a pain to implement) if we're not placing chunks
             if (placeChunks) {
-                if (((relightMode != null && relightMode != RelightMode.NONE) || (relightMode == null && Settings.settings().LIGHTING.MODE > 0))) {
+                if (this.sideEffectSet.shouldApply(SideEffect.LIGHTING) &&
-                    relighter = WorldEdit.getInstance().getPlatformManager()
+                        ((relightMode != null && relightMode != RelightMode.NONE) || (relightMode == null && Settings.settings().LIGHTING.MODE > 0))) {
+                    relighter = WorldEdit
+                            .getInstance()
+                            .getPlatformManager()
                             .queryCapability(Capability.WORLD_EDITING)
-                            .getRelighterFactory().createRelighter(relightMode, world, queue);
+                            .getRelighterFactory()
+                            .createRelighter(relightMode, world, queue);
                     queue.addProcessor(new RelightProcessor(relighter));
                 }
+                if (this.sideEffectSet.shouldApply(SideEffect.HEIGHTMAPS)) {
                     queue.addProcessor(new HeightmapProcessor(world.getMinY(), world.getMaxY()));
+                }
+                if (this.sideEffectSet.shouldApply(SideEffect.UPDATE) || this.sideEffectSet.shouldApply(SideEffect.NEIGHBORS)) {
+                    queue.addProcessor(WorldEdit
+                            .getInstance()
+                            .getPlatformManager()
+                            .queryCapability(Capability.WORLD_EDITING)
+                            .getPlatformPlacementProcessor(
+                                    queue,
+                                    null,
+                                    Settings.settings().GENERAL.PERFORM_SECOND_UPDATE_PASS,
+                                    true
+                            ));
+                }
 
                 if (!Settings.settings().EXPERIMENTAL.KEEP_ENTITIES_IN_BLOCKS) {
                     queue.addProcessor(new EntityInBlockRemovingProcessor());
@@ -710,6 +742,13 @@ public final class EditSessionBuilder {
         return changeSet;
     }
 
+    /**
+     * Get the SideEffectSet that will be used
+     */
+    public SideEffectSet getSideEffectSet() {
+        return sideEffectSet;
+    }
+
     /**
      * Get the ultimate resultant extent
      */

worldedit-core/src/main/java/com/sk89q/worldedit/LocalSession.java

@@ -1730,6 +1730,7 @@ public class LocalSession implements TextureHolder {
         }
         builder.command(command);
         builder.fastMode(!this.sideEffectSet.doesApplyAny());
+        builder.setSideEffectSet(this.sideEffectSet);
 
         editSession = builder.build();
 

worldedit-core/src/main/java/com/sk89q/worldedit/command/RegionCommands.java

@@ -41,6 +41,7 @@ import com.sk89q.worldedit.extension.platform.Actor;
 import com.sk89q.worldedit.extension.platform.Capability;
 import com.sk89q.worldedit.function.GroundFunction;
 import com.sk89q.worldedit.function.generator.FloraGenerator;
+import com.sk89q.worldedit.function.mask.BlockTypeMask;
 import com.sk89q.worldedit.function.mask.ExistingBlockMask;
 import com.sk89q.worldedit.function.mask.Mask;
 import com.sk89q.worldedit.function.mask.MaskIntersection;
@@ -903,7 +904,9 @@ public class RegionCommands {
     @Confirm(Confirm.Processor.REGION)
     @Preload(Preload.PreloadCheck.PRELOAD)
     public int fixblocks(
-            Actor actor, EditSession editSession, @Selection Region region
+            Actor actor, EditSession editSession, @Selection Region region,
+            @Switch(name = 'n', desc = "Do not perform a second pass ")
+            boolean noSecondPass
     ) {
         int affected = editSession.setBlocks(
                 region,
@@ -911,7 +914,7 @@ public class RegionCommands {
                         .getInstance()
                         .getPlatformManager()
                         .queryCapability(Capability.WORLD_EDITING)
-                        .getPlatformPlacementProcessor(editSession, null, true)
+                        .getPlatformPlacementProcessor(editSession, null, !noSecondPass, true)
         );
         if (affected != 0) {
             actor.print(Caption.of("worldedit.set.done", TextComponent.of(affected)));

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/Platform.java

@@ -284,7 +284,12 @@ public interface Platform extends Keyed {
      * Returns an {@link PlacementStateProcessor} instance for processing placed blocks to "fix" them.
      * @since TODO
      */
-    default PlacementStateProcessor getPlatformPlacementProcessor(Extent extent, BlockTypeMask mask, boolean includeUnedited) {
+    default PlacementStateProcessor getPlatformPlacementProcessor(
+            Extent extent,
+            BlockTypeMask mask,
+            boolean secondPass,
+            boolean includeUnedited
+    ) {
         return null;
     }
     //FAWE end

worldedit-core/src/main/java/com/sk89q/worldedit/function/mask/BlockTypeMask.java

@@ -149,7 +149,7 @@ public class BlockTypeMask extends AbstractExtentMask {
     }
 
     @Override
-    public Mask copy() {
+    public BlockTypeMask copy() {
         return new BlockTypeMask(getExtent(), types.clone(), hasAir);
     }
 

worldedit-core/src/main/java/com/sk89q/worldedit/util/SideEffect.java

@@ -19,23 +19,30 @@
 
 package com.sk89q.worldedit.util;
 
+import com.fastasyncworldedit.core.configuration.Settings;
+
 import java.util.Locale;
 
 public enum SideEffect {
-    LIGHTING(State.ON, true),
+    //FAWE start - adjust defaults, add history and heightmaps
-    NEIGHBORS(State.ON, true),
+    HISTORY(State.ON, true),
-    UPDATE(State.ON, true),
+    HEIGHTMAPS(State.ON, true),
+    LIGHTING(State.OFF, true), // Off defaults to falling through to config
+    NEIGHBORS(State.OFF, true),
+    UPDATE(State.OFF, true),
+    //FAWE end
     VALIDATION(State.OFF, true),
     ENTITY_AI(State.OFF, true),
     EVENTS(State.OFF, true),
     /**
      * Internal use only.
      */
-    POI_UPDATE(State.ON, false),
+    POI_UPDATE(State.OFF, false),
     /**
      * Internal use only.
      */
-    NETWORK(State.ON, false);
+    NETWORK(State.OFF, false);
+    //FAWE end
 
     private final String displayName;
     private final String description;