Bug in ResonanceMolSupplier

[ptosco]

The structure with a single positive charge yields the expected 2 resonance structures:

from rdkit import Chem
from rdkit.Chem.Draw import IPythonConsole, MolsToGridImage
IPythonConsole.drawOptions.addAtomIndices = True

mol = Chem.MolFromSmiles("O[NH+]=[C-]NC")
mol

MolsToGridImage(Chem.ResonanceMolSupplier(mol))

The analog which is also deprotonated at the iminium carbon only yields 1:

mol = Chem.MolFromSmiles("O[NH+]=[C-]NC")
mol

MolsToGridImage(Chem.ResonanceMolSupplier(mol))