#83 segfault in printing empty dataset

[Anonymous]

Minimal code to reproduce:

from ROOT import RooDataSet; RooDataSet().Print()

Output:

>>> from ROOT import RooDataSet; RooDataSet().Print()

*** Break *** segmentation violation
RooDataSet::[] =

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

Thread 2 (Thread 0x7fbd7d5dd700 (LWP 8084)):
#0 0x00007fbd83ea1fd0 in sem_wait () from /lib/x86_64-linux-gnu/libpthread.so.0
#1 0x00000000004c9eaf in PyEval_RestoreThread ()
#2 0x00000000004d59ff in ?? ()
#3 0x000000000045f912 in PyEval_EvalFrameEx ()
#4 0x0000000000467209 in PyEval_EvalCodeEx ()
#5 0x00000000004aa118 in ?? ()
#6 0x000000000046172e in PyEval_EvalFrameEx ()
#7 0x00000000004602b7 in PyEval_EvalFrameEx ()
#8 0x00000000004602b7 in PyEval_EvalFrameEx ()
#9 0x0000000000467209 in PyEval_EvalCodeEx ()
#10 0x00000000004a9fea in ?? ()
#11 0x000000000048249d in ?? ()
#12 0x000000000049629d in PyEval_CallObjectWithKeywords ()
#13 0x00000000004d8e12 in ?? ()
#14 0x00007fbd83e9be9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#15 0x00007fbd832aecbd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#16 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fbd82fa3700 (LWP 8075)):
#0 0x00007fbd8327a47d in waitpid () from /lib/x86_64-linux-gnu/libc.so.6
#1 0x00007fbd8320029e in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#2 0x00007fbd832006b0 in system () from /lib/x86_64-linux-gnu/libc.so.6
#3 0x00007fbd80fd589d in TUnixSystem::StackTrace() () from /home/endw/software/root/current/lib/libCore.so
#4 0x00007fbd80fd81a3 in TUnixSystem::DispatchSignals(ESignals) () from /home/endw/software/root/current/lib/libCore.so
#5 <signal handler called>
#6 0x00007fbd76eb2a07 in RooAbsData::numEntries() const () from /home/endw/software/root/current/lib/libRooFitCore.so
#7 0x00007fbd76f46605 in RooDataSet::printValue(std::ostream&) const () from /home/endw/software/root/current/lib/libRooFitCore.so
#8 0x00007fbd76fd806a in RooPrintable::printStream(std::ostream&, int, RooPrintable::StyleOption, TString) const () from /home/endw/software/root/current/lib/libRooFitCore.so
#9 0x00007fbd76ebfbe7 in RooAbsData::Print(char const*) const () from /home/endw/software/root/current/lib/libRooFitCore.so
#10 0x00007fbd811814f4 in G__G__Base2_10_0_45(G__value*, char const*, G__param*, int) () from /home/endw/software/root/current/lib/libCore.so
#11 0x00007fbd8047e2bf in Cint::G__CallFunc::Execute(void*) () from /home/endw/software/root/current/lib/libCint.so
#12 0x00007fbd81fd2e5c in PyROOT::TVoidExecutor::Execute(Cint::G__CallFunc*, void*) () from /home/endw/software/root/current/lib/libPyROOT.so
#13 0x00007fbd81fd873e in PyROOT::TMethodHolder<PyROOT::TScopeAdapter, PyROOT::TMemberAdapter>::CallSafe(void*) () from /home/endw/software/root/current/lib/libPyROOT.so
#14 0x00007fbd81fd88fd in PyROOT::TMethodHolder<PyROOT::TScopeAdapter, PyROOT::TMemberAdapter>::Execute(void*) () from /home/endw/software/root/current/lib/libPyROOT.so
#15 0x00007fbd81fd7b1b in PyROOT::TMethodHolder<PyROOT::TScopeAdapter, PyROOT::TMemberAdapter>::operator()(PyROOT::ObjectProxy*, _object*, _object*, long) () from /home/endw/software/root/current/lib/libPyROOT.so
#16 0x00007fbd81fdc294 in PyROOT::(anonymous namespace)::mp_call(PyROOT::MethodProxy*, _object*, _object*) () from /home/endw/software/root/current/lib/libPyROOT.so
#17 0x00000000004600be in PyEval_EvalFrameEx ()
#18 0x0000000000467209 in PyEval_EvalCodeEx ()
#19 0x00000000004d0242 in PyEval_EvalCode ()
#20 0x00000000005102bb in ?? ()
#21 0x000000000044a2c0 in PyRun_InteractiveOneFlags ()
#22 0x000000000044a3b3 in PyRun_InteractiveLoopFlags ()
#23 0x000000000044aa0f in PyRun_AnyFileExFlags ()
#24 0x000000000044b6bc in Py_Main ()
#25 0x00007fbd831dc76d in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
#26 0x00000000004ce0ad in _start ()
===========================================================

The lines below might hint at the cause of the crash.
If they do not help you then please submit a bug report at
http://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.
===========================================================
#6 0x00007fbd76eb2a07 in RooAbsData::numEntries() const () from /home/endw/software/root/current/lib/libRooFitCore.so
#7 0x00007fbd76f46605 in RooDataSet::printValue(std::ostream&) const () from /home/endw/software/root/current/lib/libRooFitCore.so
#8 0x00007fbd76fd806a in RooPrintable::printStream(std::ostream&, int, RooPrintable::StyleOption, TString) const () from /home/endw/software/root/current/lib/libRooFitCore.so
#9 0x00007fbd76ebfbe7 in RooAbsData::Print(char const*) const () from /home/endw/software/root/current/lib/libRooFitCore.so
===========================================================