The underlying reference in Unbounded_String is almost never null, so
recently it was changed to a non-excluding type (to avoid runtime checks
that are almost never needed).
The low-level routines that modify that reference had to be adapted, but
only the Deallocate routine was adapted. This patch
There are two variants of the Ada.Strings.Unbounded_String package, with
and without atomic reference counters. The underlying pointer is never
null in one variant (and had a null-excluding type) and almost never
null in the other variant (and now has a null-excluding type as well).
Cleanup relate
