GPU: Don't crash processing MC labels of empty events

Author: davidrohr

GPU/GPUTracking/Global/GPUChainTrackingClusterizer.cxx

@@ -407,7 +407,7 @@ int GPUChainTracking::RunTPCClusterizer(bool synchronizeOutput)
   ClusterNativeAccess* tmpNative = mClusterNativeAccess.get();
 
   // setup MC Labels
-  bool propagateMCLabels = GetProcessingSettings().runMC && processors()->ioPtrs.tpcPackedDigits->tpcDigitsMC != nullptr;
+  bool propagateMCLabels = GetProcessingSettings().runMC && processors()->ioPtrs.tpcPackedDigits && processors()->ioPtrs.tpcPackedDigits->tpcDigitsMC;
 
   auto* digitsMC = propagateMCLabels ? processors()->ioPtrs.tpcPackedDigits->tpcDigitsMC : nullptr;
 

GPU/GPUTracking/Global/GPUChainTrackingMerger.cxx

@@ -268,7 +268,7 @@ int GPUChainTracking::RunTPCTrackingMerger(bool synchronizeOutput)
     runKernel<GPUTPCGMO2Output, GPUTPCGMO2Output::sort>(GetGridAuto(0, deviceType), krnlRunRangeNone, krnlEventNone);
     runKernel<GPUTPCGMO2Output, GPUTPCGMO2Output::output>(GetGridAuto(0, deviceType), krnlRunRangeNone, krnlEventNone);
 
-    if (GetProcessingSettings().runMC && mIOPtrs.clustersNative->clustersMCTruth) {
+    if (GetProcessingSettings().runMC && mIOPtrs.clustersNative && mIOPtrs.clustersNative->clustersMCTruth) {
       AllocateRegisteredMemory(Merger.MemoryResOutputO2MC(), mSubOutputControls[GPUTrackingOutputs::getIndex(&GPUTrackingOutputs::tpcTracksO2Labels)]);
       TransferMemoryResourcesToHost(RecoStep::TPCMerging, &Merger, -1, true);
       runKernel<GPUTPCGMO2Output, GPUTPCGMO2Output::mc>(GetGridAuto(0, GPUReconstruction::krnlDeviceType::CPU), krnlRunRangeNone, krnlEventNone);