Merge #7072: feat(qt): introduce Wallet::startRescan() to replace append-and-restart method in Qt wallet, enable wallet rescan for multiple loaded wallets

931707c feat(qt): enable wallet rescan for multiple loaded wallets (Kittywhiskers Van Gogh)
025df83 qt: switch over to rescan wallet activity (Kittywhiskers Van Gogh)
9e16077 qt: use `QPointer` to prevent potential dangling pointer on unload (Kittywhiskers Van Gogh)
9fed372 qt: add rescan wallet activity (Kittywhiskers Van Gogh)
8b73a88 qt: add interface method to trigger rescans (Kittywhiskers Van Gogh)
9ac357b qt: de-emphasize runtime arguments, isolate code path to wallet builds (Kittywhiskers Van Gogh)

Pull request description:

  ## Motivation

  [bitcoin#23123](bitcoin#23123) removes the `-rescan` startup parameter outright and users are expected to utilise the `rescanblockchain` RPC instead. This requires us to rework how the rescan option is implemented in Dash Qt, which uses the startup parameter.

  This pull request replaces it by implementing the core rescan logic in the wallet interface (as opposed to trying to invoke an RPC call from the Qt wallet, which would violate separation of concerns) and then implementing a wallet activity to avoid blocking the main thread.

  An additional benefit of this approach is that the rescan happens immediately without the overhead of a client restart.

  ## Additional Information

  * To avoid a potential race condition where a wallet could unloaded before the rescan can be triggered, `m_rescan_wallet_model` is now a `QPointer` (which will auto-reset when the underlying entity is destroyed, [source](https://doc.qt.io/qt-6/qpointer.html)) and we do one final check in the one-shot lambda before resolving the pointer.

  ## Breaking Changes

  None expected.

  ## Checklist

  - [x] I have performed a self-review of my own code
  - [x] I have commented my code, particularly in hard-to-understand areas
  - [x] I have added or updated relevant unit/integration/functional/e2e tests **(note: N/A)**
  - [x] I have made corresponding changes to the documentation **(note: N/A)**
  - [x] I have assigned this pull request to a milestone _(for repository code-owners and collaborators only)_

ACKs for top commit:
  UdjinM6:
    light ACK 931707c

Tree-SHA512: 0a53c3e1679fbdb84f50a553ffc8513db584827b072aa9fcc5a6f6cee7b7fcd54d971741d1528bc1914671417442c433233582910a089398eff7eb7b63d1c038

Author: PastaPastaPasta

src/interfaces/wallet.h

@@ -40,6 +40,7 @@ namespace wallet {
 class CCoinControl;
 class CWallet;
 enum isminetype : unsigned int;
+enum class RescanStatus : uint8_t;
 struct CRecipient;
 struct WalletContext;
 using isminefilter = std::underlying_type<isminetype>::type;
@@ -93,6 +94,9 @@ class Wallet
     virtual bool changeWalletPassphrase(const SecureString& old_wallet_passphrase,
         const SecureString& new_wallet_passphrase) = 0;
 
+    //! Initiate a rescan. Returns status indicating success, failure, abort, or already rescanning.
+    virtual wallet::RescanStatus startRescan(bool from_genesis) = 0;
+
     //! Abort a rescan.
     virtual void abortRescan() = 0;
 

src/qt/bitcoingui.cpp

@@ -936,6 +936,8 @@ void BitcoinGUI::setWalletController(WalletController* wallet_controller, bool s
         m_wallet_controller = nullptr;
     });
 
+    rpcConsole->setWalletController(wallet_controller);
+
     auto activity = new LoadWalletsActivity(m_wallet_controller, this);
     activity->load(show_loading_minimized);
 }

src/qt/forms/debugwindow.ui

@@ -81,7 +81,7 @@
      <item>
       <widget class="QPushButton" name="btnRepair">
        <property name="text">
-        <string>&amp;Wallet Repair</string>
+        <string>&amp;Repair</string>
        </property>
        <property name="checkable">
         <bool>true</bool>
@@ -1728,7 +1728,7 @@
        <item row="0" column="0" colspan="2">
         <widget class="QLabel" name="label_repair_header">
          <property name="text">
-          <string>Wallet repair options.</string>
+          <string>Repair options.</string>
          </property>
          <property name="wordWrap">
           <bool>true</bool>
@@ -1738,7 +1738,7 @@
        <item row="1" column="0" colspan="2">
         <widget class="QLabel" name="label_repair_helptext">
          <property name="text">
-          <string>The buttons below will restart the wallet with command-line options to repair the wallet, fix issues with corrupt blockchain files or missing/obsolete transactions.</string>
+          <string>The buttons below will trigger repair actions to fix issues with corrupt files or missing/obsolete transactions.</string>
          </property>
          <property name="wordWrap">
           <bool>true</bool>
@@ -1758,14 +1758,14 @@
           </size>
          </property>
          <property name="text">
-          <string>Rescan blockchain files 1</string>
+          <string>Rescan Chain</string>
          </property>
         </widget>
        </item>
        <item row="3" column="1">
         <widget class="QLabel" name="label_repair_rescan1">
          <property name="text">
-          <string>-rescan=1: Rescan the block chain for missing wallet transactions starting from wallet creation time.</string>
+          <string>Rescan the chain for missing wallet transactions starting from wallet creation time.</string>
          </property>
          <property name="wordWrap">
           <bool>true</bool>
@@ -1781,14 +1781,14 @@
           </size>
          </property>
          <property name="text">
-          <string>Rescan blockchain files 2</string>
+          <string>Rescan Chain (full)</string>
          </property>
         </widget>
        </item>
        <item row="4" column="1">
         <widget class="QLabel" name="label_repair_rescan2">
          <property name="text">
-          <string>-rescan=2: Rescan the block chain for missing wallet transactions starting from genesis block.</string>
+          <string>Rescan the chain for missing wallet transactions starting from genesis block.</string>
          </property>
          <property name="wordWrap">
           <bool>true</bool>
@@ -1798,14 +1798,14 @@
        <item row="5" column="0">
         <widget class="QPushButton" name="btn_reindex">
          <property name="text">
-          <string>Rebuild index</string>
+          <string>Rebuild Index</string>
          </property>
         </widget>
        </item>
        <item row="5" column="1">
         <widget class="QLabel" name="label_repair_reindex">
          <property name="text">
-          <string>-reindex: Rebuild block chain index from current blk000??.dat files.</string>
+          <string>Restarts the client to rebuild the chain index from current blk000??.dat files.</string>
          </property>
          <property name="wordWrap">
           <bool>true</bool>

src/qt/rpcconsole.cpp

@@ -19,6 +19,7 @@
 #include <qt/clientmodel.h>
 #include <qt/guiutil.h>
 #include <qt/peertablesortproxy.h>
+#include <qt/walletcontroller.h>
 #include <qt/walletmodel.h>
 #include <rpc/client.h>
 #include <rpc/server.h>
@@ -70,8 +71,6 @@ const char fontSizeSettingsKey[] = "consoleFontSize";
 const TrafficGraphData::GraphRange INITIAL_TRAFFIC_GRAPH_SETTING = TrafficGraphData::Range_30m;
 
 // Repair parameters
-const QString RESCAN1("-rescan=1");
-const QString RESCAN2("-rescan=2");
 const QString REINDEX("-reindex");
 
 namespace {
@@ -574,12 +573,15 @@ RPCConsole::RPCConsole(interfaces::Node& node, QWidget* parent, Qt::WindowFlags
     ui->WalletSelector->setVisible(false);
     ui->WalletSelectorLabel->setVisible(false);
 
-    // Wallet Repair Buttons
+    // Repair Buttons
     // Disable wallet repair options that require a wallet (enable them later when a wallet is added)
     ui->btn_rescan1->setEnabled(false);
     ui->btn_rescan2->setEnabled(false);
+#ifdef ENABLE_WALLET
     connect(ui->btn_rescan1, &QPushButton::clicked, this, &RPCConsole::walletRescan1);
     connect(ui->btn_rescan2, &QPushButton::clicked, this, &RPCConsole::walletRescan2);
+    connect(ui->WalletSelector, qOverload<int>(&QComboBox::currentIndexChanged), this, &RPCConsole::onWalletChanged);
+#endif // ENABLE_WALLET
     connect(ui->btn_reindex, &QPushButton::clicked, this, &RPCConsole::walletReindex);
 
     // Register RPC timer interface
@@ -820,47 +822,41 @@ void RPCConsole::setClientModel(ClientModel *model, int bestblock_height, int64_
 }
 
 #ifdef ENABLE_WALLET
+void RPCConsole::setWalletController(WalletController* wallet_controller)
+{
+    m_wallet_controller = wallet_controller;
+}
+
 void RPCConsole::addWallet(WalletModel * const walletModel)
 {
     // use name for text and wallet model for internal data object (to allow to move to a wallet id later)
     ui->WalletSelector->addItem(walletModel->getDisplayName(), QVariant::fromValue(walletModel));
     if (ui->WalletSelector->count() == 2) {
         // First wallet added, set to default to match wallet RPC behavior
         ui->WalletSelector->setCurrentIndex(1);
-        // The only loaded wallet
-        ui->btn_rescan1->setEnabled(true);
-        ui->btn_rescan2->setEnabled(true);
-        QString wallet_path = GUIUtil::PathToQString(GetWalletDir()) + QDir::separator().toLatin1();
-        QString wallet_name = walletModel->getWalletName().isEmpty() ? "wallet.dat" : walletModel->getWalletName();
-        ui->wallet_path->setText(wallet_path + wallet_name);
-    } else {
+    }
+
+    // Update wallet path and button states for currently selected wallet
+    onWalletChanged();
+
+    // Show wallet selector when multiple wallets are loaded
+    if (ui->WalletSelector->count() > 2) {
         ui->WalletSelector->setVisible(true);
         ui->WalletSelectorLabel->setVisible(true);
-        // No wallet recovery for multiple loaded wallets
-        ui->btn_rescan1->setEnabled(false);
-        ui->btn_rescan2->setEnabled(false);
-        ui->wallet_path->clear();
     }
 }
 
 void RPCConsole::removeWallet(WalletModel * const walletModel)
 {
     ui->WalletSelector->removeItem(ui->WalletSelector->findData(QVariant::fromValue(walletModel)));
+
+    // Update wallet path and button states for currently selected wallet (or clear/disable if none)
+    onWalletChanged();
+
+    // Hide wallet selector when back to single wallet
     if (ui->WalletSelector->count() == 2) {
         ui->WalletSelector->setVisible(false);
         ui->WalletSelectorLabel->setVisible(false);
-        // Back to the only loaded wallet
-        ui->btn_rescan1->setEnabled(true);
-        ui->btn_rescan2->setEnabled(true);
-        WalletModel* wallet_model = ui->WalletSelector->itemData(1).value<WalletModel*>();
-        QString wallet_path = GUIUtil::PathToQString(GetWalletDir()) + QDir::separator().toLatin1();
-        QString wallet_name = wallet_model->getWalletName().isEmpty() ? "wallet.dat" : wallet_model->getWalletName();
-        ui->wallet_path->setText(wallet_path + wallet_name);
-    } else {
-        // No wallet recovery for multiple loaded wallets
-        ui->btn_rescan1->setEnabled(false);
-        ui->btn_rescan2->setEnabled(false);
-        ui->wallet_path->clear();
     }
 }
 
@@ -869,6 +865,24 @@ void RPCConsole::setCurrentWallet(WalletModel* const wallet_model)
     QVariant data = QVariant::fromValue(wallet_model);
     ui->WalletSelector->setCurrentIndex(ui->WalletSelector->findData(data));
 }
+
+void RPCConsole::onWalletChanged()
+{
+    WalletModel* wallet_model = ui->WalletSelector->currentData().value<WalletModel*>();
+    if (wallet_model) {
+        QString wallet_path = GUIUtil::PathToQString(GetWalletDir()) + QDir::separator().toLatin1();
+        QString wallet_name = wallet_model->getWalletName().isEmpty() ? "wallet.dat" : wallet_model->getWalletName();
+        ui->wallet_path->setText(wallet_path + wallet_name);
+        // Enable rescan buttons when a valid wallet is selected
+        ui->btn_rescan1->setEnabled(true);
+        ui->btn_rescan2->setEnabled(true);
+    } else {
+        ui->wallet_path->clear();
+        // Disable rescan buttons when no wallet is selected (e.g., "(none)")
+        ui->btn_rescan1->setEnabled(false);
+        ui->btn_rescan2->setEnabled(false);
+    }
+}
 #endif
 
 static QString categoryClass(int category)
@@ -917,17 +931,36 @@ void RPCConsole::setFontSize(int newSize)
     ui->messagesWidget->verticalScrollBar()->setValue(oldPosFactor * ui->messagesWidget->verticalScrollBar()->maximum());
 }
 
-/** Restart wallet with "-rescan=1" */
+#ifdef ENABLE_WALLET
+void RPCConsole::walletRescan(bool from_genesis)
+{
+    if (!m_wallet_controller) {
+        QMessageBox::critical(this, PACKAGE_NAME, QObject::tr("Error: Wallet controller not available."));
+        return;
+    }
+
+    WalletModel* wallet_model{ui->WalletSelector->currentData().value<WalletModel*>()};
+    if (!wallet_model) {
+        QMessageBox::critical(this, PACKAGE_NAME, QObject::tr("Error: Rescan failed. Wallet not loaded."));
+        return;
+    }
+
+    auto activity = new RescanWalletActivity(m_wallet_controller, this);
+    activity->rescan(wallet_model, from_genesis);
+}
+
+/** Rescan wallet from wallet creation */
 void RPCConsole::walletRescan1()
 {
-    buildParameterlist(RESCAN1);
+    walletRescan(/*from_genesis=*/false);
 }
 
-/** Restart wallet with "-rescan=2" */
+/** Rescan wallet from genesis block */
 void RPCConsole::walletRescan2()
 {
-    buildParameterlist(RESCAN2);
+    walletRescan(/*from_genesis=*/true);
 }
+#endif
 
 /** Restart wallet with "-reindex" */
 void RPCConsole::walletReindex()
@@ -952,8 +985,6 @@ void RPCConsole::buildParameterlist(QString arg)
     }
 
     // Remove existing repair-options
-    args.removeAll(RESCAN1);
-    args.removeAll(RESCAN2);
     args.removeAll(REINDEX);
 
     // Append repair parameter to command line.

src/qt/rpcconsole.h

@@ -24,6 +24,7 @@
 class ClientModel;
 class RPCExecutor;
 class RPCTimerInterface;
+class WalletController;
 class WalletModel;
 
 namespace interfaces {
@@ -58,6 +59,7 @@ class RPCConsole: public QWidget
     void setClientModel(ClientModel *model = nullptr, int bestblock_height = 0, int64_t bestblock_date = 0, uint256 bestblock_hash = uint256(), double verification_progress = 0.0);
 
 #ifdef ENABLE_WALLET
+    void setWalletController(WalletController* wallet_controller);
     void addWallet(WalletModel* const walletModel);
     void removeWallet(WalletModel* const walletModel);
 #endif // ENABLE_WALLET
@@ -117,10 +119,12 @@ public Q_SLOTS:
     void fontSmaller();
     void setFontSize(int newSize);
 
-    /** Wallet repair options */
+    /** Repair options */
+    void walletReindex();
+#ifdef ENABLE_WALLET
     void walletRescan1();
     void walletRescan2();
-    void walletReindex();
+#endif // ENABLE_WALLET
 
     /** Append the message to the message widget */
     void message(int category, const QString &msg) { message(category, msg, false); }
@@ -174,6 +178,12 @@ public Q_SLOTS:
     void setButtonIcons();
     /** Reload some themes related widgets */
     void reloadThemedWidgets();
+#ifdef ENABLE_WALLET
+    /** Initiate a wallet rescan */
+    void walletRescan(bool from_genesis);
+    /** Update wallet UI when selected wallet changes */
+    void onWalletChanged();
+#endif // ENABLE_WALLET
 
     enum ColumnWidths
     {
@@ -188,6 +198,7 @@ public Q_SLOTS:
     interfaces::Node& m_node;
     Ui::RPCConsole* const ui;
     ClientModel *clientModel = nullptr;
+    WalletController* m_wallet_controller{nullptr};
     QButtonGroup* pageButtons = nullptr;
     QStringList history;
     int historyPtr = 0;

src/qt/walletcontroller.cpp

@@ -514,3 +514,47 @@ void RestoreWalletActivity::finish()
 
     Q_EMIT finished();
 }
+
+RescanWalletActivity::RescanWalletActivity(WalletController* wallet_controller, QWidget* parent_widget)
+    : WalletControllerActivity(wallet_controller, parent_widget)
+{
+}
+
+void RescanWalletActivity::rescan(WalletModel* wallet_model, bool from_genesis)
+{
+    m_rescan_wallet_model = wallet_model;
+
+    QTimer::singleShot(0, worker(), [this, from_genesis] {
+        if (m_rescan_wallet_model) {
+            // Emits its own progress bar
+            m_rescan_status = m_rescan_wallet_model->wallet().startRescan(from_genesis);
+        } else {
+            // Wallet was closed before rescan could start
+            m_rescan_status = wallet::RescanStatus::FAILURE;
+        }
+        QTimer::singleShot(0, this, &RescanWalletActivity::finish);
+    });
+}
+
+void RescanWalletActivity::finish()
+{
+    switch (m_rescan_status) {
+    case wallet::RescanStatus::BUSY:
+        QMessageBox::warning(m_parent_widget, tr("Rescan unavailable"), tr("Wallet is currently rescanning. Abort existing rescan or wait."));
+        Q_EMIT rescanFailed();
+        break;
+    case wallet::RescanStatus::FAILURE:
+        QMessageBox::critical(m_parent_widget, tr("Rescan wallet failed"), tr("Rescan failed. Potentially corrupted data files."));
+        Q_EMIT rescanFailed();
+        break;
+    case wallet::RescanStatus::SUCCESS:
+        Q_EMIT rescanComplete();
+        break;
+    case wallet::RescanStatus::USER_ABORT:
+        QMessageBox::information(m_parent_widget, tr("Rescan aborted"), tr("Wallet rescan was aborted."));
+        Q_EMIT rescanFailed();
+        break;
+    }
+
+    Q_EMIT finished();
+}