Fix bug for total difficulty

ethereumj-core/src/main/java/org/ethereum/core/Block.java

@@ -166,6 +166,15 @@ public class Block {
         return this.header.getDifficulty();
     }
 
+    public BigInteger getTotalDifficulty() {
+        if (!parsed) parseRLP();
+        BigInteger totalDifficulty = new BigInteger(1, this.header.getDifficulty());
+        for (BlockHeader uncle : uncleList) {
+			totalDifficulty.add(new BigInteger(1, uncle.getDifficulty()));
+		}
+        return totalDifficulty;
+    }
+    
     public long getTimestamp() {
         if (!parsed) parseRLP();
         return this.header.getTimestamp();

ethereumj-core/src/main/java/org/ethereum/core/BlockchainImpl.java

@@ -165,19 +165,12 @@ public class BlockchainImpl implements Blockchain {
 		}
 		
 		this.addReward(block);
-		this.increaseTotalDifficulty(block);
+		this.addTotalDifficulty(block.getTotalDifficulty());
 		
         if(block.getNumber() >= CONFIG.traceStartBlock())
         	repository.dumpState(block, totalGasUsed, 0, null);
 	}
 
-	private void increaseTotalDifficulty(Block block) {
-		totalDifficulty.add(new BigInteger(block.getDifficulty()));
-		for (BlockHeader uncleHeader : block.getUncleList()) {
-			totalDifficulty.add(new BigInteger(uncleHeader.getDifficulty()));
-		}
-	}
-
 	/**
 	 * Add reward to block- and every uncle coinbase 
 	 * assuming the entire block is valid.
@@ -476,4 +469,12 @@ public class BlockchainImpl implements Blockchain {
 	public BigInteger getTotalDifficulty() {
 		return totalDifficulty;
 	}
+
+	@Override
+	public void addTotalDifficulty(BigInteger totalDifficulty) {
+		if (this.totalDifficulty == null)
+			this.totalDifficulty = totalDifficulty;
+		else
+			this.totalDifficulty.add(totalDifficulty);
+	}
 }

ethereumj-core/src/main/java/org/ethereum/db/RepositoryImpl.java

@@ -154,7 +154,7 @@ public class RepositoryImpl implements Repository {
             		Block block = new Block(iterator.next().getValue());
             		blockchain.getBlockCache().put(block.getNumber(), block.getHash());
             		blockchain.setLastBlock(block);
-
+            		blockchain.addTotalDifficulty(block.getTotalDifficulty());
                     EthereumListener listener =  WorldManager.getInstance().getListener();
                     if (listener != null){
                         listener.onPreloadedBlock(block);

ethereumj-core/src/main/java/org/ethereum/facade/Blockchain.java

@@ -21,6 +21,7 @@ public interface Blockchain  {
     public Block getLastBlock();
     public BlockQueue getQueue();
     public void close();
-	public BigInteger getTotalDifficulty();
+	public void addTotalDifficulty(BigInteger totalDifficulty);
+    public BigInteger getTotalDifficulty();
 	public byte[] getLatestBlockHash();
 }