Voting pipeline now checks for duplicated transactions in blocks during

validation.

bigchaindb/models.py

@@ -187,6 +187,11 @@ class Block(object):
         if not self.is_signature_valid():
             raise InvalidSignature('Invalid block signature')
 
+        # Check that the block contains no duplicated transactions
+        txids = [tx.id for tx in self.transactions]
+        if len(txids) != len(set(txids)):
+            raise DuplicateTransaction('Block has duplicate transaction')
+
     def _validate_block_transactions(self, bigchain):
         """Validate Block transactions.
 
@@ -196,10 +201,6 @@ class Block(object):
         Raises:
             ValidationError: If an invalid transaction is found
         """
-        txids = [tx.id for tx in self.transactions]
-        if len(txids) != len(set(txids)):
-            raise DuplicateTransaction('Block has duplicate transaction')
-
         for tx in self.transactions:
             # If a transaction is not valid, `validate_transactions` will
             # throw an an exception and block validation will be canceled.

tests/pipelines/test_vote.py

@@ -111,6 +111,18 @@ def test_validate_block_with_invalid_id(b):
     assert invalid_dummy_tx == [vote_obj.invalid_dummy_tx]
 
 
+@pytest.mark.genesis
+def test_validate_block_with_duplicated_transactions(b):
+    from bigchaindb.pipelines import vote
+
+    tx = dummy_tx(b)
+    block = b.create_block([tx, tx]).to_dict()
+
+    vote_obj = vote.Vote()
+    block_id, invalid_dummy_tx = vote_obj.validate_block(block)
+    assert invalid_dummy_tx == [vote_obj.invalid_dummy_tx]
+
+
 @pytest.mark.genesis
 def test_validate_block_with_invalid_signature(b):
     from bigchaindb.pipelines import vote

tests/test_models.py

@@ -152,4 +152,4 @@ class TestBlockModel(object):
         tx = Transaction.create([b.me], [([b.me], 1)])
         block = b.create_block([tx, tx])
         with raises(DuplicateTransaction):
-            block._validate_block_transactions(b)
+            block._validate_block(b)