Fix opening of new tabs with multiple processes

Make sure we re-use the process if the user wants a new tab.

BUG: 373440
REVIEW: 129886

src/Application.cpp

@@ -371,7 +371,6 @@ MainWindow* Application::processWindowArgs(bool &createdNewMainWindow)
 {
     MainWindow* window = 0;
     if (m_parser->isSet(QStringLiteral("new-tab"))) {
-        // topLevelsWidgets() now always returns no windows BUG:373440
         QListIterator<QWidget*> iter(QApplication::topLevelWidgets());
         iter.toBack();
         while (iter.hasPrevious()) {

src/main.cpp

@@ -121,8 +121,8 @@ extern "C" int Q_DECL_EXPORT kdemain(int argc, char* argv[])
     parser->process(args);
     about.processCommandLine(parser.data());
 
-    // Enable user to force multiple instances
-    if (!Konsole::KonsoleSettings::useSingleInstance()) {
+    // Enable user to force multiple instances, unless a new tab is requested
+    if (!Konsole::KonsoleSettings::useSingleInstance() && !parser->isSet(QStringLiteral("new-tab"))) {
         startupOption = KDBusService::Multiple;
     }