Fix some minor ordering bugs

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

@@ -192,7 +192,6 @@ public class EditSession implements Extent {
             extent = fastModeExtent = new FastModeExtent(world, false);
             extent = survivalExtent = new SurvivalModeExtent(extent, world);
             extent = quirkExtent = new BlockQuirkExtent(extent, world);
-            extent = chunkBatchingExtent = new ChunkBatchingExtent(extent);
             extent = chunkLoadingExtent = new ChunkLoadingExtent(extent, world);
             extent = cacheExtent = new LastAccessExtentCache(extent);
             extent = wrapExtent(extent, eventBus, event, Stage.BEFORE_CHANGE);
@@ -201,6 +200,7 @@ public class EditSession implements Extent {
 
             // This extent can be skipped by calling rawSetBlock()
             extent = reorderExtent = new MultiStageReorder(extent, false);
+            extent = chunkBatchingExtent = new ChunkBatchingExtent(extent);
             extent = wrapExtent(extent, eventBus, event, Stage.BEFORE_REORDER);
 
             // These extents can be skipped by calling smartSetBlock()

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

@@ -90,10 +90,14 @@ public class ChunkBatchingExtent extends AbstractDelegateExtent {
         }
         return new Operation() {
 
-            private final Iterator<LocatedBlockList> batchIterator = batches.values().iterator();
+            // we get modified between create/resume -- only create this on resume to prevent CME
+            private Iterator<LocatedBlockList> batchIterator;
 
             @Override
             public Operation resume(RunContext run) throws WorldEditException {
+                if (batchIterator == null) {
+                    batchIterator = batches.values().iterator();
+                }
                 if (!batchIterator.hasNext()) {
                     return null;
                 }