Use fee deltas for determining mempool acceptance

qa/rpc-tests/prioritise_transaction.py

@@ -143,5 +143,45 @@ class PrioritiseTransactionTest(BitcoinTestFramework):
             if (x != high_fee_tx):
                 assert(x not in mempool)
 
+        # Create a free, low priority transaction.  Should be rejected.
+        utxo_list = self.nodes[0].listunspent()
+        assert(len(utxo_list) > 0)
+        utxo = utxo_list[0]
+
+        inputs = []
+        outputs = {}
+        inputs.append({"txid" : utxo["txid"], "vout" : utxo["vout"]})
+        outputs[self.nodes[0].getnewaddress()] = utxo["amount"] - self.relayfee
+        raw_tx = self.nodes[0].createrawtransaction(inputs, outputs)
+        tx_hex = self.nodes[0].signrawtransaction(raw_tx)["hex"]
+        txid = self.nodes[0].sendrawtransaction(tx_hex)
+
+        # A tx that spends an in-mempool tx has 0 priority, so we can use it to
+        # test the effect of using prioritise transaction for mempool acceptance
+        inputs = []
+        inputs.append({"txid": txid, "vout": 0})
+        outputs = {}
+        outputs[self.nodes[0].getnewaddress()] = utxo["amount"] - self.relayfee
+        raw_tx2 = self.nodes[0].createrawtransaction(inputs, outputs)
+        tx2_hex = self.nodes[0].signrawtransaction(raw_tx2)["hex"]
+        tx2_id = self.nodes[0].decoderawtransaction(tx2_hex)["txid"]
+
+        try:
+            self.nodes[0].sendrawtransaction(tx2_hex)
+        except JSONRPCException as exp:
+            assert_equal(exp.error['code'], -26) # insufficient fee
+            assert(tx2_id not in self.nodes[0].getrawmempool())
+        else:
+            assert(False)
+
+        # This is a less than 1000-byte transaction, so just set the fee
+        # to be the minimum for a 1000 byte transaction and check that it is
+        # accepted.
+        self.nodes[0].prioritisetransaction(tx2_id, 0, int(self.relayfee*COIN))
+
+        print "Assert that prioritised free transaction is accepted to mempool"
+        assert_equal(self.nodes[0].sendrawtransaction(tx2_hex), tx2_id)
+        assert(tx2_id in self.nodes[0].getrawmempool())
+
 if __name__ == '__main__':
     PrioritiseTransactionTest().main()