companion matrix of constant polynomial has the wrong parent #34691
Description
sage: companion_matrix([QQ.one()]).parent()
Full MatrixSpace of 0 by 0 dense matrices over Integer Ring
Component: linear algebra
Author: Marc Mezzarobba
Branch/Commit: 9acf764
Reviewer: David Ayotte
Issue created by migration from https://trac.sagemath.org/ticket/34691