Re-enable buffering

This is required for masks to work properly.

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

@@ -32,6 +32,7 @@
 import com.sk89q.worldedit.extent.NullExtent;
 import com.sk89q.worldedit.extent.TracingExtent;
 import com.sk89q.worldedit.extent.buffer.ForgetfulExtentBuffer;
+import com.sk89q.worldedit.extent.buffer.internal.BatchingExtent;
 import com.sk89q.worldedit.extent.cache.LastAccessExtentCache;
 import com.sk89q.worldedit.extent.inventory.BlockBag;
 import com.sk89q.worldedit.extent.inventory.BlockBagExtent;
@@ -200,6 +201,7 @@ public String getDisplayName() {
 
     private @Nullable SideEffectExtent sideEffectExtent;
     private final SurvivalModeExtent survivalExtent;
+    private @Nullable BatchingExtent batchingExtent;
     private @Nullable ChunkBatchingExtent chunkBatchingExtent;
     private final BlockBagExtent blockBagExtent;
     @SuppressWarnings("deprecation")
@@ -269,6 +271,7 @@ public String getDisplayName() {
             this.bypassReorderHistory = traceIfNeeded(new DataValidatorExtent(extent, world));
 
             // This extent can be skipped by calling rawSetBlock()
+            extent = traceIfNeeded(batchingExtent = new BatchingExtent(extent));
             @SuppressWarnings("deprecation")
             MultiStageReorder reorder = new MultiStageReorder(extent, false);
             extent = traceIfNeeded(reorderExtent = reorder);
@@ -618,10 +621,12 @@ public void setBatchingChunks(boolean batchingChunks) {
             }
             return;
         }
+        assert batchingExtent != null : "same nullness as chunkBatchingExtent";
         if (!batchingChunks && isBatchingChunks()) {
             internalFlushSession();
         }
         chunkBatchingExtent.setEnabled(batchingChunks);
+        batchingExtent.setEnabled(!batchingChunks);
     }
 
     /**
@@ -650,6 +655,8 @@ public void disableBuffering() {
         setReorderMode(ReorderMode.NONE);
         if (chunkBatchingExtent != null) {
             chunkBatchingExtent.setEnabled(false);
+            assert batchingExtent != null : "same nullness as chunkBatchingExtent";
+            batchingExtent.setEnabled(true);
         }
     }
 

worldedit-core/src/main/java/com/sk89q/worldedit/extent/buffer/internal/BatchingExtent.java

@@ -0,0 +1,111 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.extent.buffer.internal;
+
+import com.google.common.base.Throwables;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.extent.AbstractBufferingExtent;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.function.operation.Operation;
+import com.sk89q.worldedit.function.operation.RunContext;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.collection.BlockMap;
+import com.sk89q.worldedit.world.block.BaseBlock;
+import com.sk89q.worldedit.world.block.BlockStateHolder;
+
+/**
+ * An extent that buffers all changes until completed.
+ */
+public class BatchingExtent extends AbstractBufferingExtent {
+
+    private final BlockMap<BaseBlock> blockMap = BlockMap.createForBaseBlock();
+    private boolean enabled;
+
+    public BatchingExtent(Extent extent) {
+        this(extent, true);
+    }
+
+    public BatchingExtent(Extent extent, boolean enabled) {
+        super(extent);
+        this.enabled = enabled;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+    public boolean commitRequired() {
+        return enabled;
+    }
+
+    @Override
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 location, B block) throws WorldEditException {
+        if (!enabled) {
+            return setDelegateBlock(location, block);
+        }
+        blockMap.put(location, block.toBaseBlock());
+        return true;
+    }
+
+    @Override
+    protected BaseBlock getBufferedFullBlock(BlockVector3 position) {
+        if (!enabled) {
+            // Early exit if we're not enabled.
+            return null;
+        }
+        return blockMap.get(position);
+    }
+
+    @Override
+    protected Operation commitBefore() {
+        if (!commitRequired()) {
+            return null;
+        }
+        return new Operation() {
+
+            @Override
+            public Operation resume(RunContext run) throws WorldEditException {
+                try {
+                    blockMap.forEach((position, block) -> {
+                        try {
+                            getExtent().setBlock(position, block);
+                        } catch (WorldEditException e) {
+                            throw new RuntimeException(e);
+                        }
+                    });
+                } catch (RuntimeException e) {
+                    Throwables.throwIfInstanceOf(e.getCause(), WorldEditException.class);
+                    throw e;
+                }
+                blockMap.clear();
+                return null;
+            }
+
+            @Override
+            public void cancel() {
+            }
+        };
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/extent/reorder/ChunkBatchingExtent.java

@@ -31,7 +31,6 @@
 import com.sk89q.worldedit.world.block.BlockStateHolder;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -91,18 +90,11 @@ protected Operation commitBefore() {
         }
         return new Operation() {
 
-            // we get modified between create/resume -- only create this on resume to prevent CME
-            private Iterator<BlockVector3> iterator;
-
             @Override
             public Operation resume(RunContext run) throws WorldEditException {
-                if (iterator == null) {
-                    List<BlockVector3> blockVectors = new ArrayList<>(blockMap.keySet());
-                    RegionOptimizedVectorSorter.sort(blockVectors);
-                    iterator = blockVectors.iterator();
-                }
-                while (iterator.hasNext()) {
-                    BlockVector3 position = iterator.next();
+                List<BlockVector3> blockVectors = new ArrayList<>(blockMap.keySet());
+                RegionOptimizedVectorSorter.sort(blockVectors);
+                for (BlockVector3 position : blockVectors) {
                     BaseBlock block = blockMap.get(position);
                     getExtent().setBlock(position, block);
                 }