message: Changes to V0 DCA pre-optimization procedure (more to come)
diff: @@ -1772,8 +1772,8 @@ Double_t AliAnalysisTaskWeakDecayVertexer::GetDCAV0Dau( AliExternalTrackParam *p
  Double_t vy = +ux;
  Double_t lPreprocessDCAxy = 1e+3; //define outside scope
  - Double_t lPreprocessxp = 0;
  - Double_t lPreprocessxn = 0;
  + Double_t lPreprocessxp = pt->GetX(); //start at current location
  + Double_t lPreprocessxn = nt->GetX(); //start at current location
  if( lDist > NegRadius + PosRadius ){
  //================================================================
  @@ -1802,9 +1802,11 @@ Double_t AliAnalysisTaskWeakDecayVertexer::GetDCAV0Dau( AliExternalTrackParam *p
  TMath::Power(lCase1NegR[2]-lCase1PosR[2],2)
  );
  //Pass coordinates
  + if( lPreprocessDCAxy<1e+3){
  lPreprocessxp = xThisPos;
  lPreprocessxn = xThisNeg;
  }
  + }
  //================================================================
  } else {
  //================================================================
  @@ -1908,6 +1910,11 @@ Double_t AliAnalysisTaskWeakDecayVertexer::GetDCAV0Dau( AliExternalTrackParam *p
  lPreprocessxp = lxpLargestR;
  lPreprocessxn = lxnLargestR;
  }
  + //Protection against something too crazy, please
  + if( lPreprocessDCAxy>1e+3){
  + lPreprocessxp = pt->GetX(); //start at current location
  + lPreprocessxn = nt->GetX(); //start at current location
  + }
  }
  //End of preprocessing stage!
  //at this point lPreprocessxp, lPreprocessxn are already good starting points: update helixparams
  