Bug in TBranchClones::Fill() ?

Manuel Sanchez Garcia (manuel@fpddv1.usc.es)
Thu, 26 Mar 1998 18:38:44 +0100


Hello Rooters,

I have just seen that when you try to store a TClonesArray in a
TTree using a TBranchClones with split=1. It happens that if the
TClonesArray has holes, then Root crashes when doing TTree::Fill.

To illustrate the problem i've written the following macro:

{
gROOT->Reset();
gSystem->Load("FullHades.so");
TClonesArray clones("HRichRaw",1000);
TClonesArray* pClones=&clones;
HRichRaw *pRaw;
TFile f("test.root","RECREATE");
TTree *tree=new TTree("T","Test tree");
tree->Branch("Data",&pClones,32000,1);

Int_t i,j;
for (i=0;i<10;i++) {
clones.Clear();
for (j=0;j<100;j++) {
pRaw=new(clones[j]) HRichRaw(gRandom->Gaus(3,1));
}
for (j=200;j<1000;j++) {
// if i use: "for (j=100;j<100;j++) {" then everything works
pRaw=new(clones[j]) HRichRaw(gRandom->Gaus(4,1));
}
tree->Fill();
}

f.Write();
}

This macro gives a Segmentation Violation; meanwhile if i start the
second loop in j=100 everything works Ok

Is this a bug or a feature?

Thanks in advance,

Manuel

P.D: The HRichRaw class is as follows:

class HRichRaw : public HDataObject {
public:
HRichRaw(void) : charge(0.0F) {}
// initialization could be used e.g. to clear the data element
HRichRaw(const Float_t q) : charge(q) {}
~HRichRaw(void) {}
void Clear(void) {charge=0.0F;}
Int_t getSize(void) const {return charge>0.0F ? 1:0;}
Float_t getCharge(void) const {return charge;}
void setCharge(Float_t q) {charge=q;}
friend ostream& operator<< (ostream& output, HRichRaw& element);

protected:
float charge; // Charge for each cell
ClassDef(HRichRaw,1) //Rich raw data
};