Bug in TBrowser

ROOT
1

Dear all, I experience a crash using a TBrowser on a file containing a mixture of histograms and canvases.

Here’s the code (following I will show the traceback of the crash, explain the behaviour causing the crash and, in attach, a copy of the root file).

[code]// g++ -o testTBrowser -I…/include testTBrowser.cpp root-config --cflags --libs && ./testTBrowser

#include <TApplication.h>
#include <TBrowser.h>
#include <TFile.h>

TBrowser * tBrowser_ ;
TFile * file_ ;

void doIt(void) ;

//==================================================================
int main(int argc, char** argv)
{
TApplication app(“Folders”,&argc, argv);

doIt() ;

app.Run() ;

return 0 ;
}

//==================================================================
void doIt()
{
file_ = new TFile(“JPsi_evolution.root”) ;

tBrowser_ = new TBrowser(“My files” , file_) ;

tBrowser_->Show() ;
}
[/code]

If I click on a canvas, I get the canvas displayed externally from the TBrowser, if I click on a histogram (if it’s the first thing I do), I get the histogram in the TBrowser inner canvas, but if I click on a histrogram AFTER having displayed a canvas the job crashes with the following traceback:

[quote][menasce@hercules test]$ g++ -o testTBrowser -I…/include testTBrowser.cpp root-config --cflags --libs && ./testTBrowser

*** Break *** segmentation violation

===========================================================
There was a crash.
This is the entire stack trace of all threads:

#0 0x00000036fe29a115 in waitpid () from /lib64/libc.so.6
#1 0x00000036fe23c481 in do_system () from /lib64/libc.so.6
#2 0x00002ac8bdee9c70 in TUnixSystem::StackTrace() () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#3 0x00002ac8bdee794a in TUnixSystem::DispatchSignals(ESignals) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#4
#5 0x00000036fe553a38 in main_arena () from /lib64/libc.so.6
#6 0x00002ac8c04240bb in TPad::Clear(char const*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGpad.so
#7 0x00002ac8c040bc05 in TCanvas::Clear(char const*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGpad.so
#8 0x00002ac8bf7ef505 in TH1::Draw(char const*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libHist.so
#9 0x00002ac8bf7e0160 in TH1::Browse(TBrowser*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libHist.so
#10 0x00002ac8c25c8392 in TGFileBrowser::DoubleClicked(TGListTreeItem*, int) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#11 0x00002ac8c29a0991 in G__G__Gui3_391_0_22(G__value*, char const*, G__param*, int) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#12 0x00002ac8be695dc0 in Cint::G__CallFunc::Execute(void*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCint.so
#13 0x00002ac8bdea681c in TCint::CallFunc_Exec(void*, void*) const () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#14 0x00002ac8bde4892b in TQConnection::ExecuteMethod(long*, int) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#15 0x00002ac8bde4cb78 in TQObject::Emit(char const*, long*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#16 0x00002ac8c2606b03 in TGListTree::DoubleClicked(TGListTreeItem*, int) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#17 0x00002ac8c2609d88 in TGListTree::HandleDoubleClick(Event_t*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#18 0x00002ac8c25df42f in TGFrame::HandleEvent(Event_t*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#19 0x00002ac8c25a981b in TGClient::HandleEvent(Event_t*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#20 0x00002ac8c25a9b21 in TGClient::ProcessOneEvent() () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#21 0x00002ac8c25a9b9d in TGClient::HandleInput() () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#22 0x00002ac8c25a9bbd in TGInputHandler::Notify() () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so
#23 0x00002ac8bdee72e8 in TUnixSystem::DispatchOneEvent(bool) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#24 0x00002ac8bde66bb6 in TSystem::InnerLoop() () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#25 0x00002ac8bde69741 in TSystem::Run() () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#26 0x00002ac8bde0d8af in TApplication::Run(bool) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libCore.so
#27 0x000000000040157c in main ()

The lines below might hint at the cause of the crash.
If they do not help you then please submit a bug report at
root.cern.ch/bugs. Please post the ENTIRE stack trace
from above as an attachment in addition to anything else
that might help us fixing this issue.

#5 0x00000036fe553a38 in main_arena () from /lib64/libc.so.6
#6 0x00002ac8c04240bb in TPad::Clear(char const*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGpad.so
#7 0x00002ac8c040bc05 in TCanvas::Clear(char const*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGpad.so
#8 0x00002ac8bf7ef505 in TH1::Draw(char const*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libHist.so
#9 0x00002ac8bf7e0160 in TH1::Browse(TBrowser*) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libHist.so
#10 0x00002ac8c25c8392 in TGFileBrowser::DoubleClicked(TGListTreeItem*, int) () from /gwterax3/local/root_v5.27.06-qtroot/lib/libGui.so

[/quote]

This same behavior happens in a TBrowser invoked in an interactive root session.

Any help is appreciated.

Dario
JPsi_evolution.root (1.18 MB)

2

Hi Dario,

I’m looking at this right now. I’ll keep you in touch.

Cheers, Bertrand.

3

Your histograms’ and canvases’ names contain spaces, numbers and control characters.
This makes them very hard to access from the command line. This is illegal C++.
The names should not have spaces and should contain only alphanumeric characters.
The detailed description of the object should be the title.
Can you regenerated your file with object having better names ?
I am not saying that these bad names are causing the problem, but it could be.
Let us know if it is simple for you to regenerate the file with good names.