LarentPolynomial.__call__ is broken for Laurent polynomial's that have negative exponents

[mwhansen]

sage: P.<q> = LaurentPolynomialRing(QQ)
sage: qi = q^(-1)
sage: qi in P
False
sage: q in P
True
sage: P(qi)

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)

/home/mike/<ipython console> in <module>()

/opt/sage/local/lib/python2.5/site-packages/sage/rings/polynomial/laurent_polynomial_ring.py in __call__(self, x)
    679             sage: L(1/2)
    680             1/2
    681         """
--> 682         return LaurentPolynomial_mpair(self, x)
    683     

/home/mike/laurent_polynomial.pyx in sage.rings.polynomial.laurent_polynomial.LaurentPolynomial_mpair.__init__ (sage/rings/polynomial/laurent_polynomial.c:1889)()

/home/mike/multi_polynomial_libsingular.pyx in sage.rings.polynomial.multi_polynomial_libsingular.MPolynomialRing_libsingular.__call__ (sage/rings/polynomial/multi_polynomial_libsingular.cpp:5984)()

/opt/sage/local/lib/python2.5/site-packages/sage/rings/rational_field.py in __call__(self, x, base)
    216             return x
    217 
--> 218         return sage.rings.rational.Rational(x, base)
    219         
    220     def construction(self):

/home/mike/rational.pyx in sage.rings.rational.Rational.__init__ (sage/rings/rational.c:3321)()

/home/mike/rational.pyx in sage.rings.rational.Rational.__set_value (sage/rings/rational.c:4494)()

TypeError: Unable to coerce q^-1 (<type 'sage.rings.polynomial.laurent_polynomial.LaurentPolynomial_mpair'>) to Rational

Component: commutative algebra

Author: Mike Hansen

Reviewer: Sebastian Pancratz

Merged: sage-4.3.2.alpha0

Issue created by migration from https://trac.sagemath.org/ticket/3617

[mwhansen]

Author: Mike Hansen

[mwhansen]

comment:2

This also fixes #5468.

[mwhansen]

Attachment: trac_3617.patch.gz

[sagetrac-spancratz]

comment:3

This seems fine to me, and applies and passes all doctests on 4.3.

Sebastian

[sagetrac-spancratz]

Reviewer: Sebastian Pancratz

[sagetrac-mvngu]

Merged: sage-4.3.2.alpha0