Unify bitcoin-qt and bitcoind persistent settings

doc/release-notes-15936.md

@@ -0,0 +1,15 @@
+GUI changes
+-----------
+
+Configuration changes made in the bitcoin GUI (such as the pruning setting,
+proxy settings, UPNP preferences) are now saved to `<datadir>/settings.json`
+file rather than to the Qt settings backend (windows registry or unix desktop
+config files), so these settings will now apply to bitcoind, instead of being
+ignored.
+
+Also, the interaction between GUI settings and `bitcoin.conf` settings is
+simplified. Settings from `bitcoin.conf` are now displayed normally in the GUI
+settings dialog, instead of in a separate warning message ("Options set in this
+dialog are overridden by the configuration file: -setting=value"). And these
+settings can now be edited because `settings.json` values take precedence over
+`bitcoin.conf` values.

src/qt/bitcoin.cpp

@@ -259,9 +259,26 @@ void BitcoinApplication::createPaymentServer()
 }
 #endif
 
-void BitcoinApplication::createOptionsModel(bool resetSettings)
+bool BitcoinApplication::createOptionsModel(bool resetSettings)
 {
-    optionsModel = new OptionsModel(node(), this, resetSettings);
+    optionsModel = new OptionsModel(node(), this);
+    if (resetSettings) {
+        optionsModel->Reset();
+    }
+    bilingual_str error;
+    if (!optionsModel->Init(error)) {
+        fs::path settings_path;
+        if (gArgs.GetSettingsPath(&settings_path)) {
+            error += Untranslated("\n");
+            std::string quoted_path = strprintf("%s", fs::quoted(fs::PathToString(settings_path)));
+            error.original += strprintf("Settings file %s might be corrupt or invalid.", quoted_path);
+            error.translated += tr("Settings file %1 might be corrupt or invalid.").arg(QString::fromStdString(quoted_path)).toStdString();
+        }
+        InitError(error);
+        QMessageBox::critical(nullptr, PACKAGE_NAME, QString::fromStdString(error.translated));
+        return false;
+    }
+    return true;
 }
 
 void BitcoinApplication::createWindow(const NetworkStyle *networkStyle)
@@ -327,7 +344,7 @@ void BitcoinApplication::parameterSetup()
 
 void BitcoinApplication::InitPruneSetting(int64_t prune_MiB)
 {
-    optionsModel->SetPruneTargetGB(PruneMiBtoGB(prune_MiB), true);
+    optionsModel->SetPruneTargetGB(PruneMiBtoGB(prune_MiB));
 }
 
 void BitcoinApplication::requestInitialize()
@@ -641,7 +658,9 @@ int GuiMain(int argc, char* argv[])
     app.createNode(*init);
 
     // Load GUI settings from QSettings
-    app.createOptionsModel(gArgs.GetBoolArg("-resetguisettings", false));
+    if (!app.createOptionsModel(gArgs.GetBoolArg("-resetguisettings", false))) {
+        return EXIT_FAILURE;
+    }
 
     if (did_show_intro) {
         // Store intro dialog settings other than datadir (network specific)

src/qt/bitcoin.h

@@ -47,7 +47,7 @@ class BitcoinApplication: public QApplication
     /// parameter interaction/setup based on rules
     void parameterSetup();
     /// Create options model
-    void createOptionsModel(bool resetSettings);
+    [[nodiscard]] bool createOptionsModel(bool resetSettings);
     /// Initialize prune setting
     void InitPruneSetting(int64_t prune_MiB);
     /// Create main window

src/qt/forms/optionsdialog.ui

@@ -896,7 +896,7 @@
         <item>
          <widget class="QLabel" name="overriddenByCommandLineInfoLabel">
           <property name="text">
-           <string>Options set in this dialog are overridden by the command line or in the configuration file:</string>
+           <string>Options set in this dialog are overridden by the command line:</string>
           </property>
           <property name="textFormat">
            <enum>Qt::PlainText</enum>

src/qt/optionsdialog.cpp

@@ -26,7 +26,6 @@
 #include <QIntValidator>
 #include <QLocale>
 #include <QMessageBox>
-#include <QSettings>
 #include <QSystemTrayIcon>
 #include <QTimer>
 
@@ -56,10 +55,6 @@ OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
 #ifndef USE_NATPMP
     ui->mapPortNatpmp->setEnabled(false);
 #endif
-    connect(this, &QDialog::accepted, [this](){
-        QSettings settings;
-        model->node().mapPort(settings.value("fUseUPnP").toBool(), settings.value("fUseNatpmp").toBool());
-    });
 
     ui->proxyIp->setEnabled(false);
     ui->proxyPort->setEnabled(false);