From 7c588637d467bfa18f48a7ca71c0700f90833ea1 Mon Sep 17 00:00:00 2001
From: Gregory Sanders <gsanders87@gmail.com>
Date: Fri, 28 Apr 2017 17:22:37 -0400
Subject: [PATCH] [Wallet] unset change position when there is no change on
 exact match

---
 src/wallet/wallet.cpp                 | 5 +++--
 test/functional/fundrawtransaction.py | 5 +++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index e53ac21c9..d85eedf75 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2563,9 +2563,10 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                         std::vector<CTxOut>::iterator position = txNew.vout.begin()+nChangePosInOut;
                         txNew.vout.insert(position, newTxOut);
                     }
-                }
-                else
+                } else {
                     reservekey.ReturnKey();
+                    nChangePosInOut = -1;
+                }
 
                 // Fill vin
                 //
diff --git a/test/functional/fundrawtransaction.py b/test/functional/fundrawtransaction.py
index b86ea2d87..e0ca94a6b 100755
--- a/test/functional/fundrawtransaction.py
+++ b/test/functional/fundrawtransaction.py
@@ -53,6 +53,11 @@ class RawTransactionsTest(BitcoinTestFramework):
         self.nodes[0].generate(121)
         self.sync_all()
 
+        # ensure that setting changePosition in fundraw with an exact match is handled properly
+        rawmatch = self.nodes[2].createrawtransaction([], {self.nodes[2].getnewaddress():50})
+        rawmatch = self.nodes[2].fundrawtransaction(rawmatch, {"changePosition":1, "subtractFeeFromOutputs":[0]})
+        assert_equal(rawmatch["changepos"], -1)
+
         watchonly_address = self.nodes[0].getnewaddress()
         watchonly_pubkey = self.nodes[0].validateaddress(watchonly_address)["pubkey"]
         watchonly_amount = Decimal(200)