Check by setting blocks with BlockBagExtend for changed materials.

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

@@ -86,18 +86,16 @@ public class BlockBagExtent extends AbstractDelegateExtent {
     }
 
     @Override
-//<<<<<<< HEAD
     public boolean setBlock(BlockVector3 pos, BlockStateHolder block) throws WorldEditException {
         return setBlock(pos.getBlockX(), pos.getBlockY(), pos.getBlockZ(), block);
     }
-//=======
-//    public boolean setBlock(BlockVector3 position, BlockStateHolder block) throws WorldEditException {
-//        if (blockBag != null) {
-//            BlockState existing = getExtent().getBlock(position);
-//>>>>>>> 399e0ad5... Refactor vector system to be cleaner
 
     @Override
     public boolean setBlock(int x, int y, int z, BlockStateHolder block) throws WorldEditException {
+        if(blockBag != null) {
+            BlockStateHolder lazyBlock = getExtent().getLazyBlock(x, y, z);
+            BlockType fromType = lazyBlock.getBlockType();
+        	if(!block.getBlockType().equals(fromType)) {
 				BlockType type = block.getBlockType();
 		        if (!type.getMaterial().isAir()) {
 		            try {
@@ -110,8 +108,7 @@ public class BlockBagExtent extends AbstractDelegateExtent {
 		            }
 		        }
 		        if (mine) {
-            BlockStateHolder lazyBlock = getExtent().getLazyBlock(x, y, z);
+	
-            BlockType fromType = lazyBlock.getBlockType();
 		            if (!fromType.getMaterial().isAir()) {
 		                try {
 		                    blockBag.storeDroppedBlock(fromType.getDefaultState());
@@ -119,6 +116,8 @@ public class BlockBagExtent extends AbstractDelegateExtent {
 		                }
 		            }
 		        }
+        	}
+        }
         return getExtent().setBlock(x, y, z, block);
     }