Patch for bbyy crash

The problem

It was reported that when running on a file with bypass set to true, for example with this command:

bbyy-ntupler /eos/user/a/atishelm/ntuples/SHbbyy/examples/mc20_13TeV.800904.Py8EG_A14NNPDF23LO_XHS_X170_S030_HyySbb.deriv.DAOD_PHYS.e8531_a907_r14859_p6026/DAOD_PHYS.37663611._000002.pool.root.1 --run-config bbyyAnalysis/RunConfig-Resonant-Default.yaml  --out-file analysis-variables-SHbbyy.root --e 200

or

bbyy-ntupler /eos/user/a/atishelm/ntuples/SHbbyy/examples/mc20_13TeV.800904.Py8EG_A14NNPDF23LO_XHS_X170_S030_HyySbb.deriv.DAOD_PHYS.e8531_a907_r14859_p6026/DAOD_PHYS.37663611._000002.pool.root.1 --run-config bbyyAnalysis/share/RunConfig-bbyy-skimming-loose.yaml  --out-file analysis-variables-SHbbyy.root --e 200

the following error is produced:

BaselineVarsbbyyAlg                                 FATAL  Standard std::exception is caught 
BaselineVarsbbyyAlg                                 ERROR SG::ExcBadAuxVar: Attempt to retrieve nonexistent aux data item `::selected_ph_NOSYS' (1207).

I found in particular, this error would occur for an event which had three photons, none of which passed passPhoton_TightID_NonIsoWP or passPhoton_LooseID_IsoWP.

The reason

I think a bug was introduced in !681 (merged) , as far as being compatible with the current logic of bbyyAnalysis/src/BaselineVarsbbyyAlg.cxx, as in bbyySelectorAlg.cxx, m_selected_ph is forced to have a max of two photons. However in bbyyAnalysis/src/BaselineVarsbbyyAlg.cxx, the condition if (m_selected_ph.get(*photon, sys)) will fail if the two photons don't pass passPhoton_TightID_NonIsoWP || passPhoton_LooseID_IsoWP. This means ph1 and ph2 may not be set, and if photons is > 2, it will try to access a photon which was never set in m_selected_ph.

The solution

Based on Thomas' suggestion, a decoration was added for all objects in the photons collection. In the selector, added a loop over all photons to set the decoration to false.