Protect LT-int.calculation in TRD refit from bad TPC correction

Detectors/TRD/workflow/src/TRDGlobalTrackingSpec.cxx

@@ -615,7 +615,6 @@ bool TRDGlobalTracking::refitITSTPCTRDTrack(TrackTRD& trk, float timeTRD, o2::gl
     LOG(debug) << "TRD refit outwards failed";
     return false;
   }
-
   // refit ITS-TPC-TRD track inwards to innermost ITS cluster
   // here we also calculate the LT integral for matching to TOF
   float chi2In = 0.f;
@@ -629,6 +628,12 @@ bool TRDGlobalTracking::refitITSTPCTRDTrack(TrackTRD& trk, float timeTRD, o2::gl
     LOG(debug) << "TPC refit inwards failed";
     return false;
   }
+  // if for some reason the track was overshoot over the inner field cage, bring it back w/o material correction and LTintegral update
+  if (trk.getX() < o2::constants::geom::XTPCInnerRef &&
+      !propagator->PropagateToXBxByBz(trk, o2::constants::geom::XTPCInnerRef, o2::base::Propagator::MAX_SIN_PHI, o2::base::Propagator::MAX_STEP, o2::base::Propagator::MatCorrType::USEMatCorrNONE)) {
+    LOG(debug) << "BACK-Propagationto inner boundary failed";
+    return false;
+  }
   auto posEnd = trk.getXYZGlo();
   auto lInt = propagator->estimateLTIncrement(trk, posStart, posEnd);
   trk.getLTIntegralOut().addStep(lInt, trk.getP2Inv());
@@ -718,7 +723,12 @@ bool TRDGlobalTracking::refitTPCTRDTrack(TrackTRD& trk, float timeTRD, o2::globa
   if (pileUpOn) { // account pileup time uncertainty in Z errors
     trk.updateCov(timeZErr, o2::track::CovLabels::kSigZ2);
   }
-
+  // if for some reason the track was overshoot over the inner field cage, bring it back w/o material correction and LTintegral update
+  if (trk.getX() < o2::constants::geom::XTPCInnerRef &&
+      !propagator->PropagateToXBxByBz(trk, o2::constants::geom::XTPCInnerRef, o2::base::Propagator::MAX_SIN_PHI, o2::base::Propagator::MAX_STEP, o2::base::Propagator::MatCorrType::USEMatCorrNONE)) {
+    LOG(debug) << "BACK-Propagationto inner boundary failed";
+    return false;
+  }
   auto posEnd = trk.getXYZGlo();
   auto lInt = propagator->estimateLTIncrement(trk, posStart, posEnd);
   trk.getLTIntegralOut().addStep(lInt, trk.getP2Inv());