Fix: ensure exact target X assignment in track propagation

Author: shahor02

DataFormats/Reconstruction/src/TrackParametrization.cxx

@@ -291,7 +291,7 @@ GPUd() bool TrackParametrization<value_T>::propagateParamTo(value_t xk, const di
 
   // Calculate the track parameters
   t = 1.f / gpu::CAMath::Sqrt(vecLab[3] * vecLab[3] + vecLab[4] * vecLab[4]);
-  mX = x;
+  mX = xk;
   mP[kY] = y;
   mP[kZ] = z;
   mP[kSnp] = vecLab[4] * t;

DataFormats/Reconstruction/src/TrackParametrizationWithError.cxx

@@ -568,7 +568,7 @@ GPUd() bool TrackParametrizationWithError<value_T>::propagateTo(value_t xk, cons
 
   // Calculate the track parameters
   t = 1.f / gpu::CAMath::Sqrt(vecLab[3] * vecLab[3] + vecLab[4] * vecLab[4]);
-  this->setX(x);
+  this->setX(xk);
   this->setY(y);
   this->setZ(z);
   this->setSnp(vecLab[4] * t);

Detectors/Base/src/Propagator.cxx

@@ -163,6 +163,7 @@ GPUd() bool Propagator::PropagateToXBxByBz(o2::track::TrackParCov& track, float
     }
     dx = xToGo - track.getX();
   }
+  track.setX(xToGo);
   return true;
 }
 
@@ -221,6 +222,7 @@ GPUd() bool Propagator::PropagateToXBxByBz(o2::track::TrackPar& track, float xTo
     }
     dx = xToGo - track.getX();
   }
+  track.setX(xToGo);
   return true;
 }
 
@@ -279,6 +281,7 @@ GPUd() bool Propagator::propagateToX(o2::track::TrackParCov& track, float xToGo,
     }
     dx = xToGo - track.getX();
   }
+  track.setX(xToGo);
   return true;
 }
 
@@ -337,6 +340,7 @@ GPUd() bool Propagator::propagateToX(o2::track::TrackPar& track, float xToGo, fl
     }
     dx = xToGo - track.getX();
   }
+  track.setX(xToGo);
   return true;
 }