Illegal world coordinates range when xmin>xmax

Hello again,

I have the following issue: I have a rootfile with a TTree, and this TTree contains n TBranches. I want to put the content of these TBranches in TH1F. If I do

TFile *_file0 = TFile::Open("SoftElectronMVA__BDTG_1_0_0.root") root [1] TTree *t = (TTree*)_file0->Get("TrainTree"); root [2] TIter *it = new TIter(t->GetListOfBranches()); root [7] TObject *bro = static_cast<TBranch*>(it->Next()) root [8] bro->GetName() (const char* 0x10a77239)"fbrem" root [9] TH1F* h3 = new TH1F ("h2", "h2", 100, 1, 0); root [10] t->Draw(Form("%s>>h2",bro->GetName()))

I get

Info in TCanvas::MakeDefCanvas: created default TCanvas with name c1
Error in TCanvas::Range: illegal world coordinates range: x1=1.125000, y1=-0.131250, x2=-0.125000, y2=1.181250
Error in TCanvas::RangeAxis: illegal axis coordinates range: xmin=1.000000, ymin=0.000000, xmax=0.000000, ymax=1.050000[/quote]

I thought that putting xmin>xmax would force Root to find the suitable axis range, like what is done when using TBrowser, but it seems to not appreciate. I did a very simple test with

TH1F* h3 = new TH1F ("h3", "h3", 100, 1, 0); root [5] h3->FillRandom("gaus"); root [6] h3->Draw()

and it works. Do you see anything fishy in the first trial? I use Root v5.34.

Thanks in advance