[qa] test signrawtransaction merge with missing inputs

qa/rpc-tests/signrawtransactions.py

@@ -48,6 +48,22 @@ class SignRawTransactionsTest(BitcoinTestFramework):
         # 2) No script verification error occurred
         assert 'errors' not in rawTxSigned
 
+        # Check that signrawtransaction doesn't blow up on garbage merge attempts
+        dummyTxInconsistent = self.nodes[0].createrawtransaction([inputs[0]], outputs)
+        rawTxUnsigned = self.nodes[0].signrawtransaction(rawTx + dummyTxInconsistent, inputs)
+
+        assert 'complete' in rawTxUnsigned
+        assert_equal(rawTxUnsigned['complete'], False)
+
+        # Check that signrawtransaction properly merges unsigned and signed txn, even with garbage in the middle
+        rawTxSigned2 = self.nodes[0].signrawtransaction(rawTxUnsigned["hex"] + dummyTxInconsistent + rawTxSigned["hex"], inputs)
+
+        assert 'complete' in rawTxSigned2
+        assert_equal(rawTxSigned2['complete'], True)
+
+        assert 'errors' not in rawTxSigned2
+
+
     def script_verification_error_test(self):
         """Creates and signs a raw transaction with valid (vin 0), invalid (vin 1) and one missing (vin 2) input script.