Conversion to polynomials over symbolic ring doesn't work properly

[soehms]

The problem occured in context with #4618 (see comment 32) and is explained by the following code:

sage: PS = PolynomialRing(SR,'x')
sage: P = PolynomialRing(QQ,'x')
sage: q = P((1,1,5)); q
5*x^2 + x + 1
sage: p = PS(q)
sage: p.coefficients()
[5*x^2 + x + 1]
p in SR
True

Component: coercion

Keywords: symbolic ring days100

Issue created by migration from https://trac.sagemath.org/ticket/28238

[embray]

comment:1

Ticket retargeted after milestone closed

[mkoeppe]

comment:2

Moving tickets to milestone sage-9.2 based on a review of last modification date, branch status, and severity.

[mkoeppe]

comment:4

Sage development has entered the release candidate phase for 9.3. Setting a new milestone for this ticket based on a cursory review.