Require non-zero coefficient ring in power series ring

src/RelSeries.jl

@@ -1473,8 +1473,10 @@ object `S` will be cached so that supplying the same base ring, string and
 precision in future will return the same parent object and generator. If
 caching of the parent object is not required, `cached` can be set to `false`.
 """
-power_series_ring(R::Ring, prec::Int, s::VarName; cached::Bool=true, model::Symbol=:capped_relative) =
-   Generic.power_series_ring(R, prec, Symbol(s); cached, model)
+function power_series_ring(R::Ring, prec::Int, s::VarName; cached::Bool=true, model::Symbol=:capped_relative)
+   @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
+   return Generic.power_series_ring(R, prec, Symbol(s); cached, model)
+end
 
 function AbsPowerSeriesRing(R::Ring, prec::Int)
    T = elem_type(R)

src/generic/AbsMSeries.jl

@@ -709,6 +709,8 @@ end
 
 function power_series_ring(R::AbstractAlgebra.Ring, prec::Vector{Int},
                   s::Vector{Symbol}; cached::Bool=true, model=:capped_absolute)
+
+    @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
     U = elem_type(R)
 
     S, _ = AbstractAlgebra.polynomial_ring(R, s)
@@ -724,6 +726,8 @@ end
 function power_series_ring(R::AbstractAlgebra.Ring, prec::Int,
         s::Vector{Symbol}; weights::Union{Vector{Int}, Nothing}=nothing,
         cached::Bool=true, model=:capped_absolute)
+
+    @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
     U = elem_type(R)
 
     S, _ = AbstractAlgebra.polynomial_ring(R, s)

src/generic/RelSeries.jl

@@ -419,6 +419,7 @@ end
 ###############################################################################
 
 function power_series_ring(R::AbstractAlgebra.Ring, prec::Int, s::VarName; cached::Bool=true, model::Symbol=:capped_relative)
+   @req !is_trivial(R) "Zero rings are currently not supported as coefficient ring."
    T = elem_type(R)
 
    if model == :capped_relative