[Qgis-developer] addFeatures without knowing new feature's id, bug?

[Denis Rouzaud]

Hi again!

I am trying to add a feature to a PostGIS table, in which there is a 
serial primary key 'id'.

Without defining id, here is what I get when I try addFeatures:
ERROR: null value in column "id" violates not-null constraint

and I tried
iid  = self.layer.dataProvider().fieldNameIndex('id')
if iid != -1: 
f.addAttribute(iid,'nextval(distribution.dimension_id_seq::regclass)')
which leaded to
ERROR: invalid input syntax for integer: 
"nextval(distribution.dimension_id_seq::regclass)"

Is there a bug in the provider, or should I get first the new id (if 
yes, how do I do this) ?

Thanks a lot!
Denis