In Sage-5.0 we have

sage: toric_varieties.P2().Kaehler_cone().lattice()
The toric rational divisor class group of a 2-d CPR-Fano toric variety covered by 3 affine patches
sage: _.base_ring()
Rational Field

which is wrong since this lattice is not a lattice.

CC: @vbraun

Component: algebraic geometry

Keywords: toric, sd40.5

Author: Andrey Novoseltsev

Reviewer: Volker Braun

Merged: sage-5.2.beta1

Issue created by migration from https://trac.sagemath.org/ticket/12965