Merge bitcoin#17965: qt: Revert changes of pr17943

70e4706 Revert "refactor: Remove never used default parameter" (Hennadii Stepanov)
219417b Revert "refactor: Simplify connection syntax" (Hennadii Stepanov)

Pull request description:

  The code, the `bool* ret = nullptr` parameter in the `BitcoinGUI::message()` slot, removed in bitcoin#17943 is not dead actually. It is used in `ThreadSafeMessageBox()` function:
  https://github.com/bitcoin/bitcoin/blob/a654626f076a72416a3d354218d7107571d6caaf/src/qt/bitcoingui.cpp#L1363-L1368

  Now in master (a654626):
  ```
  $ ./src/qt/bitcoin-qt -prune=-1
  Error: Prune cannot be configured with a negative value.
  bitcoin-qt: qt/bitcoingui.cpp:1369: bool ThreadSafeMessageBox(BitcoinGUI*, const string&, const string&, unsigned int): Assertion `invoked' failed.
  Aborted (core dumped)
  ```

  This PR reverts all commits of bitcoin#17943

  Additional notes: the bug was missed due to dynamic function call `QMetaObject::invokeMethod()` which cannot be checked at compile time. See bitcoin#16348 for more discussion.

  Sorry for introducing a bug.

ACKs for top commit:
  Sjors:
    ACK 70e4706
  laanwj:
    ACK 70e4706

Tree-SHA512: b968a026eaa4f5f39fd36ddc715d8e233f3c6420e6580f11d4ca422a5ff5d1d9d3df9ac11b353c3d4f434d67d6a69e37d2e26b8248d72bedd14ecba0a545a327

src/qt/bitcoingui.cpp

@@ -801,7 +801,9 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel)
         connect(_clientModel, &ClientModel::additionalDataSyncProgressChanged, this, &BitcoinGUI::setAdditionalDataSyncProgress);
 
         // Receive and report messages from client model
-        connect(_clientModel, &ClientModel::message, this, &BitcoinGUI::message);
+        connect(_clientModel, &ClientModel::message, [this](const QString &title, const QString &message, unsigned int style){
+            this->message(title, message, style);
+        });
 
         // Show progress dialog
         connect(_clientModel, &ClientModel::showProgress, this, &BitcoinGUI::showProgress);
@@ -1504,7 +1506,7 @@ void BitcoinGUI::setAdditionalDataSyncProgress(double nSyncProgress)
     progressBar->setToolTip(tooltip);
 }
 
-void BitcoinGUI::message(const QString& title, QString message, unsigned int style)
+void BitcoinGUI::message(const QString& title, QString message, unsigned int style, bool* ret)
 {
     // Default title. On macOS, the window title is ignored (as required by the macOS Guidelines).
     QString strTitle{PACKAGE_NAME};
@@ -1558,7 +1560,9 @@ void BitcoinGUI::message(const QString& title, QString message, unsigned int sty
         showNormalIfMinimized();
         QMessageBox mBox(static_cast<QMessageBox::Icon>(nMBoxIcon), strTitle, message, buttons, this);
         mBox.setTextFormat(Qt::PlainText);
-        mBox.exec();
+        int r = mBox.exec();
+        if (ret != nullptr)
+            *ret = r == QMessageBox::Ok;
     } else {
         notificator->notify(static_cast<Notificator::Class>(nNotifyIcon), strTitle, message);
     }

src/qt/bitcoingui.h

@@ -260,8 +260,9 @@ public Q_SLOTS:
        @param[in] message   the displayed text
        @param[in] style     modality and style definitions (icon and used buttons - buttons only for message boxes)
                             @see CClientUIInterface::MessageBoxFlags
+       @param[in] ret       pointer to a bool that will be modified to whether Ok was clicked (modal only)
     */
-    void message(const QString& title, QString message, unsigned int style);
+    void message(const QString& title, QString message, unsigned int style, bool* ret = nullptr);
 
 #ifdef ENABLE_WALLET
     void setCurrentWallet(WalletModel* wallet_model);

src/qt/dash.cpp

@@ -387,7 +387,9 @@ void BitcoinApplication::initializeResult(bool success)
         if (paymentServer) {
             connect(paymentServer, &PaymentServer::receivedPaymentRequest, window, &BitcoinGUI::handlePaymentRequest);
             connect(window, &BitcoinGUI::receivedURI, paymentServer, &PaymentServer::handleURIOrFile);
-            connect(paymentServer, &PaymentServer::message, window, &BitcoinGUI::message);
+            connect(paymentServer, &PaymentServer::message, [this](const QString& title, const QString& message, unsigned int style) {
+                window->message(title, message, style);
+            });
             QTimer::singleShot(100, paymentServer, &PaymentServer::uiReady);
         }
 #endif

src/qt/walletview.cpp

@@ -134,7 +134,9 @@ void WalletView::setBitcoinGUI(BitcoinGUI *gui)
         connect(coinJoinCoinsPage, &SendCoinsDialog::coinsSent, gui, &BitcoinGUI::gotoHistoryPage);
 
         // Receive and report messages
-        connect(this, &WalletView::message, gui, &BitcoinGUI::message);
+        connect(this, &WalletView::message, [gui](const QString &title, const QString &message, unsigned int style) {
+            gui->message(title, message, style);
+        });
 
         // Pass through encryption status changed signals
         connect(this, &WalletView::encryptionStatusChanged, gui, &BitcoinGUI::updateWalletStatus);