Merge #14879: qt: Add warning messages to the debug window

593ba696fb Add warning messages to the debug window (Hennadii Stepanov)

Pull request description:

  Fix: #11016

  This PR adds warning messages to the debug window in `-disablewallet` mode.

  ![screenshot from 2018-12-06 01-01-27](https://user-images.githubusercontent.com/32963518/49550070-413c1c80-f8f3-11e8-9865-efb49ea8da45.png)

ACKs for top commit:
  jonasschnelli:
    utACK 593ba696fb
  promag:
    ACK 593ba696fb, agree with @Sjors https://github.com/bitcoin/bitcoin/pull/14879#pullrequestreview-196433092 above.
  ryanofsky:
    utACK 593ba696fb

Tree-SHA512: a8ca78529bb16813ba7bfaf5ccd4349189979f08e78ea857746a6fb00fd9d7ed98d8f06f384830acba21dac57070060af23f6be8249398feb32a6efff1333de8

src/qt/rpcconsole.cpp

@@ -558,6 +558,17 @@ bool RPCConsole::eventFilter(QObject* obj, QEvent *event)
 void RPCConsole::setClientModel(ClientModel *model)
 {
     clientModel = model;
+
+    bool wallet_enabled{false};
+#ifdef ENABLE_WALLET
+    wallet_enabled = WalletModel::isWalletEnabled();
+#endif // ENABLE_WALLET
+    if (model && !wallet_enabled) {
+        // Show warning, for example if this is a prerelease version
+        connect(model, &ClientModel::alertsChanged, this, &RPCConsole::updateAlerts);
+        updateAlerts(model->getStatusBarWarnings());
+    }
+
     ui->trafficGraph->setClientModel(model);
     if (model && clientModel->getPeerTableModel() && clientModel->getBanTableModel()) {
         // Keep up to date with client
@@ -1274,3 +1285,9 @@ QString RPCConsole::tabTitle(TabTypes tab_type) const
 {
     return ui->tabWidget->tabText(tab_type);
 }
+
+void RPCConsole::updateAlerts(const QString& warnings)
+{
+    this->ui->label_alerts->setVisible(!warnings.isEmpty());
+    this->ui->label_alerts->setText(warnings);
+}