GUI: Save any TBC settings in a parallel setting key

Author: luke-jr

src/qt/bitcoinunits.cpp

@@ -346,7 +346,7 @@ BitcoinUnit FromQint8(qint8 num)
     case 2: return BitcoinUnit::uBTC;
     case 3: return BitcoinUnit::SAT;
     }
-    assert(false);
+    return BitcoinUnit::BTC;
 }
 
 BitcoinUnit FromSetting(const QString& s, BitcoinUnit def)

src/qt/optionsmodel.cpp

@@ -163,6 +163,9 @@ bool OptionsModel::Init(bilingual_str& error)
         settings.setValue("DisplayBitcoinUnit", QVariant::fromValue(BitcoinUnit::BTC));
     }
     QVariant unit = settings.value("DisplayBitcoinUnit");
+    if (settings.contains("DisplayBitcoinUnitKnots")) {
+        unit = settings.value("DisplayBitcoinUnitKnots");
+    }
     if (unit.canConvert<BitcoinUnit>()) {
         m_display_bitcoin_unit = unit.value<BitcoinUnit>();
     } else {
@@ -653,7 +656,12 @@ void OptionsModel::setDisplayUnit(const QVariant& new_unit)
     if (new_unit.isNull() || new_unit.value<BitcoinUnit>() == m_display_bitcoin_unit) return;
     m_display_bitcoin_unit = new_unit.value<BitcoinUnit>();
     QSettings settings;
-    settings.setValue("DisplayBitcoinUnit", QVariant::fromValue(m_display_bitcoin_unit));
+    if (BitcoinUnits::numsys(m_display_bitcoin_unit) == BitcoinUnit::BTC) {
+        settings.setValue("DisplayBitcoinUnit", QVariant::fromValue(m_display_bitcoin_unit));
+        settings.remove("DisplayBitcoinUnitKnots");
+    } else {
+        settings.setValue("DisplayBitcoinUnitKnots", QVariant::fromValue(m_display_bitcoin_unit));
+    }
     Q_EMIT displayUnitChanged(m_display_bitcoin_unit);
 }