Merge #602: Unify bitcoin-qt and bitcoind persistent settings

e47c6c7 Reset settings.json when GUI options are reset (Ryan Ofsky)
99ccc02 Add release notes about unified bitcoin-qt and bitcoind persistent settings (Ryan Ofsky)
504b06b Migrate -lang setting from QSettings to settings.json (Ryan Ofsky)
9a016a3 Migrate -prune setting from QSettings to settings.json (Ryan Ofsky)
f067e19 Migrate -proxy and -onion settings from QSettings to settings.json (Ryan Ofsky)
a09e3b7 Migrate -listen and -server settings from QSettings to settings.json (Ryan Ofsky)
d2ada6e Migrate -upnp and -natpmp settings from QSettings to settings.json (Ryan Ofsky)
1dc4fc2 Migrate -spendzeroconfchange and -signer settings from QSettings to settings.json (Ryan Ofsky)
a7ef6d5 Migrate -par setting from QSettings to settings.json (Ryan Ofsky)
284f339 Migrate -dbcache setting from QSettings to settings.json (Ryan Ofsky)

Pull request description:

  If a setting like pruning, port mapping, or a network proxy is enabled in the GUI, it will now be stored in the bitcoin persistent setting file in the datadir and shared with bitcoind, instead of being stored as Qt settings which end up in the the windows registry or platform specific config files and are ignored by bitcoind.

  This PR has been split off from bitcoin/bitcoin#15936 so some review of these commits previously took place in that PR.

ACKs for top commit:
  furszy:
    Code review ACK e47c6c7
  hebasto:
    ACK e47c6c7

Tree-SHA512: 076ea7c7efe67805b4a357113bfe1643dce364d0032774106de59566a0ed5771d57a5923920085e03d686beb34b98114bd278555dfdf8bb7af0b778b0f35b7d2

Author: hebasto

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);