OpenFileManagerWindowJob: fix opening multiple instances under Wayland
The Problem: Under wayland, when there's only one Dolphin window, "Show Target" in Dolphin's right click menu opens multiple duplicate Dolphin windows.
The Cause: DolphinMainWindow::showTarget => KIO::OpenFileManagerWindowJob::highlightInFileManager => KWindowSystem::requestXdgActivationToken => on KWindowSystem::xdgActivationTokenArrived signal => dbus call org.freedesktop.FileManager1 ShowItems => Dolphin::DBusInterface::ShowItems => Dolphin::openNewWindow => KIO::ApplicationLauncherJob => KIO::KProcessRunner => Calls KWindowSystem::requestXdgActivationToken under Wayland. Loop.
The Fix: Pass Qt::SingleShotConnection flag to QObject::connect() to avoid the loop.
Edited by Jin Liu