Reactions don't propagate bond properties

[d-b-w]

I'm using a custom build of RDKit 2021.03 on Mac.

It looks like RDKit reactions don't preserve bond properties from the reactants. Is this intentional?

from rdkit import Chem
from rdkit.Chem import rdChemReactions

rxn = rdChemReactions.ReactionFromSmarts('[O:1]>>[N:1]')

mol = Chem.MolFromSmiles('CCO')

mol.GetAtomWithIdx(0).SetIntProp('demo', 1)
reactant_bond = mol.GetBondBetweenAtoms(0, 1)
reactant_bond.SetIntProp('demo', 1)

product_groups = rxn.RunReactants([mol])
product = product_groups[0][0]

mapping = {int(a.GetProp('react_atom_idx')): a.GetIdx() for a in product.GetAtoms()}
product_bond = product.GetBondBetweenAtoms(mapping[0], mapping[1])
print(product_bond.GetPropsAsDict())

This shows no properties on the bond, and only the mapping properties on the atoms.

[d-b-w]

Somebody from sdgr will fix this, as long as we agree that it is a bug.

[greglandrum]

Sorry I forgot to reply to this earlier: I agree that this is a bug.

[ricrogz]

Dibs!

[bp-kelley]

In c++ land there is a function that might be useful:

  void RDProps::updateProps(const RDProps &source, bool preserveExisting = false) {
    d_props.update(source.getDict(), preserveExisting);
  }

To copy properties from one thing to another ala:

new_bond.updateProps(old_bond);