any_root() sometimes fails over finite fields

[saraedum]

sage: K.<a> = GF(2^4)
sage: R.<x> = K[]
sage: f = x^2 + x + a^2 + a
sage: f.any_root()
ValueError
sage: f.any_root()
a

The algorithm is randomized. It sometimes fails because of a typo.

CC: @roed314

Component: finite rings

Author: Julian Rüth

Branch/Commit: e5bcffa

Reviewer: David Roe

Issue created by migration from https://trac.sagemath.org/ticket/21998

[saraedum]

Branch: u/saraedum/any_root___sometimes_fails_over_finite_fields

[saraedum]

Commit: ec1b78b

[saraedum]

New commits:

ec1b78b

fix typo in any_root()

[roed314]

Reviewer: David Roe

[roed314]

comment:4

Oops. Looks good.

[vbraun]

comment:5

I'm getting

6082sage -t --long src/sage/rings/polynomial/polynomial_element.pyx
6083**********************************************************************
6084File "src/sage/rings/polynomial/polynomial_element.pyx", line 1777, in sage.rings.polynomial.polynomial_element.Polynomial.any_root
6085Failed example:
6086    (x**2+x+1).any_root() # used to loop
6087Expected:
6088    Traceback (most recent call last):
6089    ...
6090    ValueError: no roots A 1
6091Got:
6092    a^7 + a^6 + a^4 + a^2 + a + 1
6093**********************************************************************
6094File "src/sage/rings/polynomial/polynomial_element.pyx", line 1810, in sage.rings.polynomial.polynomial_element.Polynomial.any_root
6095Failed example:
6096    f.any_root()
6097Expected:
6098    a
6099Got:
6100    a + 1
6101**********************************************************************
61021 item had failures:
6103   2 of  34 in sage.rings.polynomial.polynomial_element.Polynomial.any_root
6104    [2127 tests, 2 failures, 54.92 s]

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

1c38d17	Fix any_root() doctest
e5bcffa	Fix doctest

[sagetrac-git]

Changed commit from ec1b78b to e5bcffa

[roed314]

comment:8

If the patchbot gives it a thumbs up, you can go ahead and set it to positive review.

[vbraun]

Changed branch from u/saraedum/any_root___sometimes_fails_over_finite_fields to e5bcffa