forming ideals in IntegerModRing_generic does not work #5666
Description
It is impossible to create ideals in rings of the form Integers mod n:
sage: R = Integers(10)
sage: R.ideal(1)
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
/home/masgaj/.sage/temp/host_56_150/5831/_home_masgaj__sage_init_sage_0.py
in <module>()
/local/jec/sage-3.4.1.alpha0/local/lib/python2.5/site-packages/sage/rings/quotient_ring.pyc
in ideal(self, *gens, **kwds)
487 gens = gens[0]
488 from
sage.rings.polynomial.multi_polynomial_libsingular import
MPolynomialRing_libsingular
--> 489 if not
isinstance(self.__R,MPolynomialRing_libsingular) and not
self.__R._has_singular:
490 # pass through
491 MPolynomialRing_generic.ideal(self,gens,**kwds)
AttributeError: 'sage.rings.integer_ring.IntegerRing_class' object has
no attribute '_has_singular'
sage: R.ideal([2,4])
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
(as above)
It looks as if the ideal() method for class QuotientRing_generic is
only really geared to polynomial ring quotients.
Component: algebra
Author: William Stein
Reviewer: Rob Beezer
Merged: sage-4.3.1.rc1
Issue created by migration from https://trac.sagemath.org/ticket/5666