The bug is in multiplication algorithm: in sage/rings/polynomial/polynomial_real_mpfr_dense.pyx in function that does ring multiplication: cpdef RingElement _mul_(left, RingElement _right): there is line 431: cdef PolynomialRealDense f = left._new(left._degree + right._degree) that is creates a polynomial of degee -2 (!!!) if both elements we multiply are 0, and so have degrees -1. I have created a trac ticket: #8211
The patch I uploaded there apparently fixes the problem. Best, Dima On Feb 7, 6:49 pm, Kiran Kedlaya <ksk...@gmail.com> wrote: > The following input segfaults sage 4.3.2 on sage.math, as well as sage > 4.3 on various other machines. > > P.<x> = PolynomialRing(RealField()) > print sum(P(0)*P(0) for k in range(1)) > > This example seems quite fragile; for instance, the segfault goes away > if you change RealField to RationalField, RealDoubleField, or Complex > Field. > > Kiran -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
