extracting coefficient x-1 out of symbolic series wrong

[dkrenn]

sage: x.series(x==1,10).coefficient(x-1,0)
x

which is wrong. It should be 1, which can be seen by

sage: x.series(x==1,10)
1 + 1*(x - 1)

We also have wrong results here:

sage: x.series(x==1,10).coefficient(x-1,1)
0
sage: x.series(x==1,10).coefficient(x-1)
0

Component: symbolics

Keywords: symbolic, series, coefficient, wrong

Issue created by migration from https://trac.sagemath.org/ticket/15830

[rwst]

comment:3

Also coefficient can only deal with monomials:

sage: (x-1).coefficient(x-1)
0

Different ticket?