From 5564dfccb03cee115e080a157222ec0c787fab8a Mon Sep 17 00:00:00 2001
From: Aditya Kulkarni <adityapk@gmail.com>
Date: Thu, 14 Mar 2019 10:38:16 -0700
Subject: [PATCH] Prevent deleting utxos and balances while updating

---
 src/rpc.cpp | 25 +++++++++++++++----------
 src/rpc.h   |  2 +-
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/src/rpc.cpp b/src/rpc.cpp
index b3db556..a1bb293 100644
--- a/src/rpc.cpp
+++ b/src/rpc.cpp
@@ -713,7 +713,7 @@ void RPC::updateUI(bool anyUnconfirmed) {
 };
 
 // Function to process reply of the listunspent and z_listunspent API calls, used below.
-bool RPC::processUnspent(const json& reply) {
+bool RPC::processUnspent(const json& reply, QMap<QString, double>* balancesMap, QList<UnspentOutput>* newUtxos) {
     bool anyUnconfirmed = false;
     for (auto& it : reply.get<json::array_t>()) {
         QString qsAddr = QString::fromStdString(it["address"]);
@@ -722,12 +722,12 @@ bool RPC::processUnspent(const json& reply) {
             anyUnconfirmed = true;
         }
 
-        utxos->push_back(
+        newUtxos->push_back(
             UnspentOutput{ qsAddr, QString::fromStdString(it["txid"]),
                             Settings::getDecimalString(it["amount"].get<json::number_float_t>()),
                             (int)confirmations, it["spendable"].get<json::boolean_t>() });
 
-        (*allBalances)[qsAddr] = (*allBalances)[qsAddr] + it["amount"].get<json::number_float_t>();
+        (*balancesMap)[qsAddr] = (*balancesMap)[qsAddr] + it["amount"].get<json::number_float_t>();
     }
     return anyUnconfirmed;
 };
@@ -754,18 +754,23 @@ void RPC::refreshBalances() {
     });
 
     // 2. Get the UTXOs
-    // First, create a new UTXO list, deleting the old one;
-    delete utxos;
-    utxos = new QList<UnspentOutput>();
-    delete allBalances;
-    allBalances = new QMap<QString, double>();
+    // First, create a new UTXO list. It will be replacing the existing list when everything is processed.
+    auto newUtxos = new QList<UnspentOutput>();
+    auto newBalances = new QMap<QString, double>();
 
     // Call the Transparent and Z unspent APIs serially and then, once they're done, update the UI
     getTransparentUnspent([=] (json reply) {
-        auto anyTUnconfirmed = processUnspent(reply);
+        auto anyTUnconfirmed = processUnspent(reply, newBalances, newUtxos);
 
         getZUnspent([=] (json reply) {
-            auto anyZUnconfirmed = processUnspent(reply);
+            auto anyZUnconfirmed = processUnspent(reply, newBalances, newUtxos);
+
+            // Swap out the balances and UTXOs
+            delete allBalances;
+            delete utxos;
+
+            allBalances = newBalances;
+            utxos       = newUtxos;
 
             updateUI(anyTUnconfirmed || anyZUnconfirmed);    
         });        
diff --git a/src/rpc.h b/src/rpc.h
index 720f286..ec41e70 100644
--- a/src/rpc.h
+++ b/src/rpc.h
@@ -94,7 +94,7 @@ private:
     void refreshSentZTrans();
     void refreshReceivedZTrans(QList<QString> zaddresses);
 
-    bool processUnspent     (const json& reply);
+    bool processUnspent     (const json& reply, QMap<QString, double>* newBalances, QList<UnspentOutput>* newUtxos);
     void updateUI           (bool anyUnconfirmed);
 
     void getInfoThenRefresh(bool force);