Added loop detection to _Flatten.  It was doing half of the work, putting an undefined value in the cache for any new attribute reference it saw.  However, it was not searching the cache to see if the attribute reference had been prevously encountered.
Added loop detection to _Flatten.  It was doing half of the work, putting an
undefined value in the cache for any new attribute reference it saw.  However,
it was not searching the cache to see if the attribute reference had been
prevously encountered.

zhangzhehust/htcondor,djw8605/condor,zhangzhehust/htcondor,bbockelm/condor-network-accounting,clalancette/condor-dcloud,htcondor/htcondor,djw8605/htcondor,neurodebian/htcondor,djw8605/condor,zhangzhehust/htcondor,mambelli/osg-bosco-marco,htcondor/htcondor,zhangzhehust/htcondor,djw8605/htcondor,djw8605/htcondor,mambelli/osg-bosco-marco,clalancette/condor-dcloud,djw8605/htcondor,mambelli/osg-bosco-marco,neurodebian/htcondor,djw8605/condor,mambelli/osg-bosco-marco,bbockelm/condor-network-accounting,djw8605/htcondor,htcondor/htcondor,htcondor/htcondor,djw8605/condor,neurodebian/htcondor,bbockelm/condor-network-accounting,htcondor/htcondor,clalancette/condor-dcloud,zhangzhehust/htcondor,neurodebian/htcondor,mambelli/osg-bosco-marco,djw8605/htcondor,neurodebian/htcondor,zhangzhehust/htcondor,htcondor/htcondor,zhangzhehust/htcondor,bbockelm/condor-network-accounting,djw8605/htcondor,bbockelm/condor-network-accounting,neurodebian/htcondor,bbockelm/condor-network-accounting,mambelli/osg-bosco-marco,djw8605/condor,bbockelm/condor-network-accounting,neurodebian/htcondor,djw8605/condor,neurodebian/htcondor,htcondor/htcondor,djw8605/htcondor,clalancette/condor-dcloud,zhangzhehust/htcondor,clalancette/condor-dcloud,bbockelm/condor-network-accounting,neurodebian/htcondor,clalancette/condor-dcloud,djw8605/htcondor,mambelli/osg-bosco-marco,mambelli/osg-bosco-marco,zhangzhehust/htcondor,clalancette/condor-dcloud,htcondor/htcondor,djw8605/condor,djw8605/condor