Use can disconnect links on window close prompt

src/qgcunittest/MainWindowTest.cc

@@ -81,8 +81,8 @@ void MainWindowTest::_connectWindowClose_test(void)
     linkMgr->connectLink(link);
     QTest::qWait(5000); // Give enough time for UI to settle and heartbeats to go through
     
-    // On MainWindow close we should get a message box telling the user to disconnect first
-    setExpectedMessageBox(QGCMessageBox::Ok);
+    // On MainWindow close we should get a message box telling the user to disconnect first. Cancel should do nothing.
+    setExpectedMessageBox(QGCMessageBox::Cancel);
     _mainWindow->close();
     QTest::qWait(1000); // Need to allow signals to move between threads    
     checkExpectedMessageBox();

src/ui/MainWindow.cc

@@ -787,11 +787,23 @@ void MainWindow::closeEvent(QCloseEvent *event)
     }
     
     if (foundConnections) {
-        QGCMessageBox::warning(tr("QGroundControl close"), tr("There are still active connections to vehicles. Please disconnect all connections before closing QGroundControl."));
-        event->ignore();
-        return;
+        QGCMessageBox::StandardButton button = QGCMessageBox::warning(tr("QGroundControl close"),
+                                                                      tr("There are still active connections to vehicles. Do you want to disconnect these before closing?"),
+                                                                      QMessageBox::Yes | QMessageBox::Cancel,
+                                                                      QMessageBox::Cancel);
+        if (button == QMessageBox::Yes) {
+            foreach(LinkInterface* link, LinkManager::instance()->getLinks()) {
+                LinkManager::instance()->disconnectLink(link);
+            }
+        } else {
+            event->ignore();
+            return;
+        }
     }
 
+    // This will process any remaining flight log save dialogs
+    qgcApp()->processEvents(QEventLoop::ExcludeUserInputEvents);
+
     // Should not be any active connections
     foreach(LinkInterface* link, LinkManager::instance()->getLinks()) {
         Q_UNUSED(link);