Inserting into a table with identity column using select distinct

[CR #401753] If you have enabled parallel plan, and use select distinct into a table with an identity column and one of the select distinct list items is an expression or an implicit convert() expression, this query may cause a stack trace. Here is an example query:

create table tt(id numeric(5) identity not null, c1 int,
    c2 int) 
go
insert into tt select distinct c1, c2+1 from t
go

Workaround: Disable parallel plan for the query. For the example query, use:

insert into tt select distinct c1, c2+1 from t (parallel 1)