Add a material to check if air is air, because there are now 3 types of air.

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

@@ -60,6 +60,11 @@ public class BukkitBlockRegistry extends BundledBlockRegistry {
             this.material = bukkitMaterial;
         }
 
+        @Override
+        public boolean isAir() {
+            return material == Material.AIR || material == Material.CAVE_AIR || material == Material.VOID_AIR;
+        }
+
         @Override
         public boolean isSolid() {
             return material.isSolid();

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

@@ -64,7 +64,7 @@ public class BukkitPlayerBlockBag extends BlockBag {
 
     @Override
     public void fetchBlock(BlockState blockState) throws BlockBagException {
-        if (blockState.getBlockType() == BlockTypes.AIR) {
+        if (blockState.getBlockType().getMaterial().isAir()) {
             throw new IllegalArgumentException("Can't fetch air block");
         }
 
@@ -108,7 +108,7 @@ public class BukkitPlayerBlockBag extends BlockBag {
 
     @Override
     public void storeBlock(BlockState blockState, int amount) throws BlockBagException {
-        if (blockState.getBlockType() == BlockTypes.AIR) {
+        if (blockState.getBlockType().getMaterial().isAir()) {
             throw new IllegalArgumentException("Can't store air block");
         }
         if (!blockState.getBlockType().hasItemType()) {

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

@@ -59,7 +59,7 @@ public class EditSessionBlockChangeDelegate implements BlockChangeDelegate {
 
     @Override
     public boolean isEmpty(int x, int y, int z) {
-        return editSession.getBlock(new Vector(x, y, z)).getBlockType() == BlockTypes.AIR;
+        return editSession.getBlock(new Vector(x, y, z)).getBlockType().getMaterial().isAir();
     }
 
 }

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

@@ -1446,7 +1446,7 @@ public class EditSession implements Extent {
                         if (setBlock(pt, air)) {
                             ++affected;
                         }
-                    } else if (id == BlockTypes.AIR) {
+                    } else if (id.getMaterial().isAir()) {
                         continue;
                     }
 
@@ -1488,7 +1488,7 @@ public class EditSession implements Extent {
                     Vector pt = new Vector(x, y, z);
                     BlockType id = getBlock(pt).getBlockType();
 
-                    if (id == BlockTypes.AIR) {
+                    if (id.getMaterial().isAir()) {
                         continue;
                     }
 
@@ -1619,7 +1619,7 @@ public class EditSession implements Extent {
             for (int z = basePosition.getBlockZ() - size; z <= basePosition.getBlockZ()
                     + size; ++z) {
                 // Don't want to be in the ground
-                if (getBlock(new Vector(x, basePosition.getBlockY(), z)).getBlockType() != BlockTypes.AIR) {
+                if (!getBlock(new Vector(x, basePosition.getBlockY(), z)).getBlockType().getMaterial().isAir()) {
                     continue;
                 }
                 // The gods don't want a tree here
@@ -1636,7 +1636,7 @@ public class EditSession implements Extent {
                         break;
                     } else if (t == BlockTypes.SNOW) {
                         setBlock(new Vector(x, y, z), BlockTypes.AIR.getDefaultState());
-                    } else if (t != BlockTypes.AIR) { // Trees won't grow on this!
+                    } else if (!t.getMaterial().isAir()) { // Trees won't grow on this!
                         break;
                     }
                 }

worldedit-core/src/main/java/com/sk89q/worldedit/command/tool/AreaPickaxe.java

@@ -54,7 +54,7 @@ public class AreaPickaxe implements BlockTool {
         int oz = clicked.getBlockZ();
         BlockType initialType = clicked.getExtent().getBlock(clicked.toVector()).getBlockType();
 
-        if (initialType == BlockTypes.AIR) {
+        if (initialType.getMaterial().isAir()) {
             return true;
         }
 

worldedit-core/src/main/java/com/sk89q/worldedit/command/tool/FloatingTreeRemover.java

@@ -134,7 +134,7 @@ public class FloatingTreeRemover implements BlockTool {
 
                 if (visited.add(next)) {
                     BlockState state = world.getBlock(next);
-                    if (state.getBlockType() == BlockTypes.AIR || state.getBlockType() == BlockTypes.SNOW) {
+                    if (state.getBlockType().getMaterial().isAir() || state.getBlockType() == BlockTypes.SNOW) {
                         continue;
                     }
                     if (isTreeBlock(state.getBlockType())) {

worldedit-core/src/main/java/com/sk89q/worldedit/command/tool/FloodFillTool.java

@@ -61,7 +61,7 @@ public class FloodFillTool implements BlockTool {
 
         BlockType initialType = world.getBlock(clicked.toVector()).getBlockType();
 
-        if (initialType == BlockTypes.AIR) {
+        if (initialType.getMaterial().isAir()) {
             return true;
         }
 

worldedit-core/src/main/java/com/sk89q/worldedit/command/tool/LongRangeBuildTool.java

@@ -57,7 +57,7 @@ public class LongRangeBuildTool extends BrushTool implements DoubleActionTraceTo
         EditSession eS = session.createEditSession(player);
         try {
             BlockStateHolder applied = secondary.apply(pos.toVector());
-            if (applied.getBlockType() == BlockTypes.AIR) {
+            if (applied.getBlockType().getMaterial().isAir()) {
                 eS.setBlock(pos.toVector(), secondary);
             } else {
                 eS.setBlock(pos.getDirection(), secondary);
@@ -77,7 +77,7 @@ public class LongRangeBuildTool extends BrushTool implements DoubleActionTraceTo
         EditSession eS = session.createEditSession(player);
         try {
             BlockStateHolder applied = primary.apply(pos.toVector());
-            if (applied.getBlockType() == BlockTypes.AIR) {
+            if (applied.getBlockType().getMaterial().isAir()) {
                 eS.setBlock(pos.toVector(), primary);
             } else {
                 eS.setBlock(pos.getDirection(), primary);

worldedit-core/src/main/java/com/sk89q/worldedit/command/tool/RecursivePickaxe.java

@@ -58,7 +58,7 @@ public class RecursivePickaxe implements BlockTool {
 
         BlockType initialType = world.getBlock(clicked.toVector()).getBlockType();
 
-        if (initialType == BlockTypes.AIR) {
+        if (initialType.getMaterial().isAir()) {
             return true;
         }
 

worldedit-core/src/main/java/com/sk89q/worldedit/command/tool/brush/GravityBrush.java

@@ -48,7 +48,7 @@ public class GravityBrush implements Brush {
                 for (; y > position.getBlockY() - size; --y) {
                     final Vector pt = new Vector(x, y, z);
                     final BlockStateHolder block = editSession.getBlock(pt);
-                    if (block.getBlockType() != BlockTypes.AIR) {
+                    if (!block.getBlockType().getMaterial().isAir()) {
                         blockTypes.add(block);
                         editSession.setBlock(pt, BlockTypes.AIR.getDefaultState());
                     }
@@ -56,7 +56,7 @@ public class GravityBrush implements Brush {
                 Vector pt = new Vector(x, y, z);
                 Collections.reverse(blockTypes);
                 for (int i = 0; i < blockTypes.size();) {
-                    if (editSession.getBlock(pt).getBlockType() == BlockTypes.AIR) {
+                    if (editSession.getBlock(pt).getBlockType().getMaterial().isAir()) {
                         editSession.setBlock(pt, blockTypes.get(i++));
                     }
                     pt = pt.add(0, 1, 0);

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

@@ -32,6 +32,7 @@ import com.sk89q.worldedit.util.TargetBlock;
 import com.sk89q.worldedit.util.auth.AuthorizationException;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
+import com.sk89q.worldedit.world.block.BlockType;
 import com.sk89q.worldedit.world.block.BlockTypes;
 import com.sk89q.worldedit.world.gamemode.GameMode;
 import com.sk89q.worldedit.world.gamemode.GameModes;
@@ -210,10 +211,10 @@ public abstract class AbstractPlayerActor implements Actor, Player, Cloneable {
                 while (y >= 0) {
                     final Vector platform = new Vector(x, y, z);
                     final BlockStateHolder block = world.getBlock(platform);
-                    final com.sk89q.worldedit.world.block.BlockType type = block.getBlockType();
+                    final BlockType type = block.getBlockType();
 
                     // Don't want to end up in lava
-                    if (type != BlockTypes.AIR && type != BlockTypes.LAVA) {
+                    if (!type.getMaterial().isAir() && type != BlockTypes.LAVA) {
                         // Found a block!
                         setPosition(platform.add(0.5, 1, 0.5));
                         return true;
@@ -246,7 +247,7 @@ public abstract class AbstractPlayerActor implements Actor, Player, Cloneable {
         Extent world = getLocation().getExtent();
 
         // No free space above
-        if (world.getBlock(new Vector(x, y, z)).getBlockType() != BlockTypes.AIR) {
+        if (!world.getBlock(new Vector(x, y, z)).getBlockType().getMaterial().isAir()) {
             return false;
         }
 

worldedit-core/src/main/java/com/sk89q/worldedit/extent/inventory/BlockBag.java

@@ -37,7 +37,7 @@ public abstract class BlockBag {
     public void storeDroppedBlock(BlockState blockState) throws BlockBagException {
         BlockState dropped = blockState; // TODO BlockType.getBlockBagItem(id, data);
         if (dropped == null) return;
-        if (dropped.getBlockType() == BlockTypes.AIR) return;
+        if (dropped.getBlockType().getMaterial().isAir()) return;
 
         storeBlock(dropped);
     }
@@ -57,7 +57,7 @@ public abstract class BlockBag {
             fetchBlock(blockState);
         } catch (OutOfBlocksException e) {
             BlockState placed = blockState;// TODO BlockType.getBlockBagItem(id, data);
-            if (placed == null || placed.getBlockType() == BlockTypes.AIR) throw e; // TODO: check
+            if (placed == null || placed.getBlockType().getMaterial().isAir()) throw e; // TODO: check
 
             fetchBlock(placed);
         }

worldedit-core/src/main/java/com/sk89q/worldedit/extent/inventory/BlockBagExtent.java

@@ -87,7 +87,7 @@ public class BlockBagExtent extends AbstractDelegateExtent {
         if (blockBag != null) {
             BlockState existing = getExtent().getBlock(position);
 
-            if (block.getBlockType() != BlockTypes.AIR) {
+            if (!block.getBlockType().getMaterial().isAir()) {
                 try {
                     blockBag.fetchPlacedBlock(block.toImmutableState());
                 } catch (UnplaceableBlockException e) {
@@ -102,7 +102,7 @@ public class BlockBagExtent extends AbstractDelegateExtent {
                 }
             }
 
-            if (existing.getBlockType() != BlockTypes.AIR) {
+            if (!existing.getBlockType().getMaterial().isAir()) {
                 try {
                     blockBag.storeDroppedBlock(existing);
                 } catch (BlockBagException ignored) {

worldedit-core/src/main/java/com/sk89q/worldedit/extent/world/SurvivalModeExtent.java

@@ -81,7 +81,7 @@ public class SurvivalModeExtent extends AbstractDelegateExtent {
 
     @Override
     public boolean setBlock(Vector location, BlockStateHolder block) throws WorldEditException {
-        if (toolUse && block.getBlockType() == BlockTypes.AIR) {
+        if (toolUse && block.getBlockType().getMaterial().isAir()) {
             world.simulateBlockMine(location);
             return true;
         } else {

worldedit-core/src/main/java/com/sk89q/worldedit/function/generator/GardenPatchGenerator.java

@@ -86,11 +86,11 @@ public class GardenPatchGenerator implements RegionFunction {
      */
     private void placeVine(Vector basePos, Vector pos) throws MaxChangedBlocksException {
         if (pos.distance(basePos) > 4) return;
-        if (editSession.getBlock(pos).getBlockType() != BlockTypes.AIR) return;
+        if (!editSession.getBlock(pos).getBlockType().getMaterial().isAir()) return;
 
         for (int i = -1; i > -3; --i) {
             Vector testPos = pos.add(0, i, 0);
-            if (editSession.getBlock(testPos).getBlockType() == BlockTypes.AIR) {
+            if (editSession.getBlock(testPos).getBlockType().getMaterial().isAir()) {
                 pos = testPos;
             } else {
                 break;
@@ -159,7 +159,7 @@ public class GardenPatchGenerator implements RegionFunction {
 
     @Override
     public boolean apply(Vector position) throws WorldEditException {
-        if (editSession.getBlock(position).getBlockType() != BlockTypes.AIR) {
+        if (!editSession.getBlock(position).getBlockType().getMaterial().isAir()) {
             position = position.add(0, 1, 0);
         }
 
@@ -169,7 +169,7 @@ public class GardenPatchGenerator implements RegionFunction {
 
         BlockState leavesBlock = BlockTypes.OAK_LEAVES.getDefaultState();
 
-        if (editSession.getBlock(position).getBlockType() == BlockTypes.AIR) {
+        if (editSession.getBlock(position).getBlockType().getMaterial().isAir()) {
             editSession.setBlock(position, leavesBlock);
         }
 
@@ -199,7 +199,7 @@ public class GardenPatchGenerator implements RegionFunction {
      * @throws MaxChangedBlocksException thrown if too many blocks are changed
      */
     private static boolean setBlockIfAir(EditSession session, Vector position, BlockStateHolder block) throws MaxChangedBlocksException {
-        return session.getBlock(position).getBlockType() == BlockTypes.AIR && session.setBlock(position, block);
+        return session.getBlock(position).getBlockType().getMaterial().isAir() && session.setBlock(position, block);
     }
 
     /**

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

@@ -42,7 +42,7 @@ public class ExistingBlockMask extends AbstractExtentMask {
 
     @Override
     public boolean test(Vector vector) {
-        return getExtent().getBlock(vector).getBlockType() != BlockTypes.AIR;
+        return !getExtent().getBlock(vector).getBlockType().getMaterial().isAir();
     }
 
     @Nullable

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

@@ -102,7 +102,7 @@ public class TargetBlock {
         boolean searchForLastBlock = true;
         Location lastBlock = null;
         while (getNextBlock() != null) {
-            if (world.getBlock(getCurrentBlock().toVector()).getBlockType() == BlockTypes.AIR) {
+            if (world.getBlock(getCurrentBlock().toVector()).getBlockType().getMaterial().isAir()) {
                 if (searchForLastBlock) {
                     lastBlock = getCurrentBlock();
                     if (lastBlock.getBlockY() <= 0 || lastBlock.getBlockY() >= world.getMaxY()) {
@@ -124,7 +124,7 @@ public class TargetBlock {
      * @return Block
      */
     public Location getTargetBlock() {
-        while (getNextBlock() != null && world.getBlock(getCurrentBlock().toVector()).getBlockType() == BlockTypes.AIR) ;
+        while (getNextBlock() != null && world.getBlock(getCurrentBlock().toVector()).getBlockType().getMaterial().isAir()) ;
         return getCurrentBlock();
     }
 

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

@@ -264,6 +264,6 @@ public class TreeGenerator {
      * @throws MaxChangedBlocksException thrown if too many blocks are changed
      */
     private static boolean setBlockIfAir(EditSession session, Vector position, BlockStateHolder block) throws MaxChangedBlocksException {
-        return session.getBlock(position).getBlockType() == BlockTypes.AIR && session.setBlock(position, block);
+        return session.getBlock(position).getBlockType().getMaterial().isAir() && session.setBlock(position, block);
     }
 }

worldedit-core/src/main/java/com/sk89q/worldedit/world/chunk/OldChunk.java

@@ -154,7 +154,7 @@ public class OldChunk implements Chunk {
 
     @Override
     public BaseBlock getBlock(Vector position) throws DataException {
-        if(position.getBlockY() >= 128) BlockTypes.AIR.getDefaultState().toBaseBlock();
+        if(position.getBlockY() >= 128) BlockTypes.VOID_AIR.getDefaultState().toBaseBlock();
         int id, dataVal;
 
         int x = position.getBlockX() - rootX * 16;

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/BlockMaterial.java

@@ -24,6 +24,13 @@ package com.sk89q.worldedit.world.registry;
  */
 public interface BlockMaterial {
 
+    /**
+     * Gets if this block is a type of air.
+     *
+     * @return If it's air
+     */
+    boolean isAir();
+
     /**
      * Get whether this block is a full sized cube.
      *

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/PassthroughBlockMaterial.java

@@ -29,6 +29,15 @@ public class PassthroughBlockMaterial implements BlockMaterial {
         this.blockMaterial = material;
     }
 
+    @Override
+    public boolean isAir() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isAir();
+        }
+    }
+
     @Override
     public boolean isFullCube() {
         if (blockMaterial == null) {

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/SimpleBlockMaterial.java

@@ -21,6 +21,7 @@ package com.sk89q.worldedit.world.registry;
 
 class SimpleBlockMaterial implements BlockMaterial {
 
+    private boolean isAir;
     private boolean fullCube;
     private boolean opaque;
     private boolean powerSource;
@@ -40,6 +41,15 @@ class SimpleBlockMaterial implements BlockMaterial {
     private boolean isTranslucent;
     private boolean hasContainer;
 
+    @Override
+    public boolean isAir() {
+        return this.isAir;
+    }
+
+    public void setIsAir(boolean isAir) {
+        this.isAir = isAir;
+    }
+
     @Override
     public boolean isFullCube() {
         return fullCube;