fix: fix stack overflow when converting Term to non-concrete coefficient type

Author: AayushSabharwal

src/conversion.jl

@@ -58,6 +58,9 @@ function Base.convert(TT::Type{<:AbstractTerm{T}}, t::AbstractTerm) where {T}
         ),
     )
 end
+function Base.convert(::Type{Term{T, M}}, t::AbstractTerm) where {T, M}
+    return Term{T, M}(convert(T, coefficient(t)), convert(M, monomial(t)))
+end
 
 # Base.convert(::Type{T}, t::T) where {T <: AbstractTerm} is ambiguous with above method.
 # we need the following:

test/commutative/term.jl

@@ -63,6 +63,9 @@ MP.term_type(::Type{Term2{T,M}}) where {T,M} = MP.Term{T,M}
     @test_throws InexactError push!([1], 2x)
     @test_throws InexactError push!([x^2], 2x)
 
+    t = MP.term(1, x)
+    @test convert(MP.Term{Number, MP.monomial_type(t)}, t) isa MP.Term{Number, MP.monomial_type(t)}
+
     @testset "Effective variables" begin
         T = variable_union_type(x)
         @test x isa T