From 792985162682d1c124cf6da4f79c7d24bc9f8352 Mon Sep 17 00:00:00 2001
From: Eirik Ogilvie-Wigley <eirik@z.cash>
Date: Wed, 1 Aug 2018 14:16:04 -0600
Subject: [PATCH] Only include the change field if we have a spending key

---
 qa/rpc-tests/wallet_changeindicator.py | 13 +++++++++++++
 src/wallet/rpcwallet.cpp               | 17 +++++++++++------
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/qa/rpc-tests/wallet_changeindicator.py b/qa/rpc-tests/wallet_changeindicator.py
index 58b431fc2..d26381064 100755
--- a/qa/rpc-tests/wallet_changeindicator.py
+++ b/qa/rpc-tests/wallet_changeindicator.py
@@ -60,5 +60,18 @@ class WalletChangeIndicatorTest (BitcoinTestFramework):
         assert_equal(Decimal('0.6'), sortedunspent[1]['amount'])
         assert_false(sortedunspent[1]['change'], "Unspent note valued at 0.6 should not be change")
 
+        # Give node 0 a viewing key
+        viewing_key = self.nodes[1].z_exportviewingkey(zaddr1)
+        self.nodes[0].z_importviewingkey(viewing_key)
+        received_node0 = self.nodes[0].z_listreceivedbyaddress(zaddr1, 0)
+        assert_equal(2, len(received_node0))
+        unspent_node0 = self.nodes[0].z_listunspent(1, 9999999, True)
+        assert_equal(2, len(unspent_node0))
+        # node 0 only has a viewing key so does not see the change field
+        assert_false('change' in received_node0[0])
+        assert_false('change' in received_node0[1])
+        assert_false('change' in unspent_node0[0])
+        assert_false('change' in unspent_node0[1])
+
 if __name__ == '__main__':
     WalletChangeIndicatorTest().main()
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index e93781636..0d7861aa2 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2565,12 +2565,15 @@ UniValue z_listunspent(const UniValue& params, bool fHelp)
             obj.push_back(Pair("jsindex", (int)entry.jsop.js ));
             obj.push_back(Pair("jsoutindex", (int)entry.jsop.n));
             obj.push_back(Pair("confirmations", entry.nHeight));
-            obj.push_back(Pair("spendable", pwalletMain->HaveSproutSpendingKey(boost::get<libzcash::SproutPaymentAddress>(entry.address))));
+            bool hasSproutSpendingKey = pwalletMain->HaveSproutSpendingKey(boost::get<libzcash::SproutPaymentAddress>(entry.address));
+            obj.push_back(Pair("spendable", hasSproutSpendingKey));
             obj.push_back(Pair("address", EncodePaymentAddress(entry.address)));
             obj.push_back(Pair("amount", ValueFromAmount(CAmount(entry.plaintext.value()))));
             std::string data(entry.plaintext.memo().begin(), entry.plaintext.memo().end());
             obj.push_back(Pair("memo", HexStr(data)));
-            obj.push_back(Pair("change", pwalletMain->IsNoteChange(nullifierSet, entry.address, entry.jsop)));
+            if (hasSproutSpendingKey) {
+                obj.push_back(Pair("change", pwalletMain->IsNoteChange(nullifierSet, entry.address, entry.jsop)));
+            }
             results.push_back(obj);
         }
     }
@@ -3296,15 +3299,15 @@ UniValue z_listreceivedbyaddress(const UniValue& params, bool fHelp)
     assert(boost::get<libzcash::SproutPaymentAddress>(&zaddr) != nullptr);
     auto sproutzaddr = boost::get<libzcash::SproutPaymentAddress>(zaddr);
 
-    if (!(pwalletMain->HaveSproutSpendingKey(sproutzaddr) || pwalletMain->HaveSproutViewingKey(sproutzaddr))) {
+    bool hasSproutSpendingKey = pwalletMain->HaveSproutSpendingKey(sproutzaddr);
+    if (!(hasSproutSpendingKey || pwalletMain->HaveSproutViewingKey(sproutzaddr))) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "From address does not belong to this node, zaddr spending key or viewing key not found.");
     }
 
-
     UniValue result(UniValue::VARR);
     std::vector<CSproutNotePlaintextEntry> entries;
     pwalletMain->GetFilteredNotes(entries, fromaddress, nMinDepth, false, false);
-    std::set<std::pair<PaymentAddress, uint256>> nullifierSet = pwalletMain->GetNullifiersForAddresses({zaddr});
+    auto nullifierSet = hasSproutSpendingKey ? pwalletMain->GetNullifiersForAddresses({zaddr}) : std::set<std::pair<PaymentAddress, uint256>>();
     for (CSproutNotePlaintextEntry & entry : entries) {
         UniValue obj(UniValue::VOBJ);
         obj.push_back(Pair("txid", entry.jsop.hash.ToString()));
@@ -3314,7 +3317,9 @@ UniValue z_listreceivedbyaddress(const UniValue& params, bool fHelp)
         // (txid, jsindex, jsoutindex) is needed to globally identify a note
         obj.push_back(Pair("jsindex", entry.jsop.js));
         obj.push_back(Pair("jsoutindex", entry.jsop.n));
-        obj.push_back(Pair("change", pwalletMain->IsNoteChange(nullifierSet, entry.address, entry.jsop)));
+        if (hasSproutSpendingKey) {
+            obj.push_back(Pair("change", pwalletMain->IsNoteChange(nullifierSet, entry.address, entry.jsop)));
+        }
         result.push_back(obj);
     }
     return result;