[sage-devel] QQbar.simplify() or minpoly() don't work

['Paul Mercat' via sage-devel]

Hi !

I have a problem with this example:

sage: b = (x^7 - 2*x^6 + x^3 - 2*x^2 + 2*x - 1).roots(ring=QQbar)[3][0]
sage: b.abs().minpoly()

It doesn't terminates ! (In fact it finished a very long tilme after with a
pari stack overflow.)
(If I do b.abs().simplify(), the result is the same).

But if I do this computation in an other way, it works (it takes only a few
seconds):

sage: b = (x^7 - 2*x^6 + x^3 - 2*x^2 + 2*x - 1).roots(ring=QQbar)[3][0]
sage: y = b*b.conjugate()
sage: y.simplify()
sage: sqrt(y).minpoly()

If I don't do the step y.simplify(), the computation doesn't terminates (or
at least it takes more than 15min).

Computations in QQbar should be improved...
Is it possible to make sage use the second way to compute the minpoly of
b.abs() ?

Paul