Fixes #402

- Similar to previous commit. If the chunksection was empty, then __reserved__ was parsed to the clipboard, and then not correctly identified as air
- Now assume all __reserved__ is air when writing to clipboards

worldedit-core/src/main/java/com/boydti/fawe/object/clipboard/CPUOptimizedClipboard.java

@@ -184,7 +184,11 @@ public class CPUOptimizedClipboard extends LinearClipboard {
 
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(int index, B block) {
-        states[index] = block.getOrdinalChar();
+        char ordinal = block.getOrdinalChar();
+        if (ordinal == 0) {
+            ordinal = 1;
+        }
+        states[index] = ordinal;
         boolean hasNbt = block instanceof BaseBlock && block.hasNbtData();
         if (hasNbt) {
             setTile(index, block.getNbtData());

worldedit-core/src/main/java/com/boydti/fawe/object/clipboard/DiskOptimizedClipboard.java

@@ -388,6 +388,9 @@ public class DiskOptimizedClipboard extends LinearClipboard implements Closeable
         try {
             int index = HEADER_SIZE + (getIndex(x, y, z) << 1);
             char ordinal = block.getOrdinalChar();
+            if (ordinal == 0) {
+                ordinal = 1;
+            }
             byteBuffer.putChar(index, ordinal);
             boolean hasNbt = block instanceof BaseBlock && block.hasNbtData();
             if (hasNbt) {

worldedit-core/src/main/java/com/boydti/fawe/object/clipboard/MemoryOptimizedClipboard.java

@@ -263,6 +263,9 @@ public class MemoryOptimizedClipboard extends LinearClipboard {
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(int index, B block) {
         int ordinal = block.getOrdinal();
+        if (ordinal == 0) {
+            ordinal = 1;
+        }
         setOrdinal(index, ordinal);
         boolean hasNbt = block instanceof BaseBlock && block.hasNbtData();
         if (hasNbt) {