Also do provider-based backend selection when querying alternatives

autotests/timelinedelegatecontrollertest.cpp

@@ -157,6 +157,7 @@ private Q_SLOTS:
     {
         ReservationManager mgr;
         Test::clearAll(&mgr);
+        LiveDataManager ldm;
         ApplicationController ctrl;
         ctrl.setReservationManager(&mgr);
         ctrl.importFromUrl(QUrl::fromLocalFile(QLatin1String(SOURCE_DIR "/../tests/randa2017.json")));
@@ -164,6 +165,7 @@ private Q_SLOTS:
         TimelineDelegateController controller;
         controller.setReservationManager(&mgr);
         controller.setBatchId(mgr.batches().at(0)); // flight
+        controller.setLiveDataManager(&ldm);
         QVERIFY(!controller.journeyRequest().isValid());
 
         controller.setBatchId(mgr.batches().at(1)); // first train segment

src/app/timelinedelegatecontroller.cpp

@@ -403,7 +403,7 @@ static bool isLayover(const QVariant &res1, const QVariant &res2)
 
 KPublicTransport::JourneyRequest TimelineDelegateController::journeyRequest() const
 {
-    if (!m_resMgr || m_batchId.isEmpty()) {
+    if (!m_resMgr || m_batchId.isEmpty() || !m_liveDataMgr) {
         return {};
     }
 
@@ -420,6 +420,7 @@ KPublicTransport::JourneyRequest TimelineDelegateController::journeyRequest() co
     req.setDownloadAssets(true);
     req.setIncludeIntermediateStops(true);
     req.setIncludePaths(true);
+    PublicTransport::selectBackends(req, m_liveDataMgr->publicTransportManager(), res);
 
     // find full journey by looking at subsequent elements
     auto prevRes = res;