[Bug c++/91826] [8/9/10 Regression] Unexpected behavior when class defined with namespace alias

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91826

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2019-09-23
                 CC|                            |nathan at gcc dot gnu.org
      Known to work|                            |7.4.0
            Summary|Unexpected behavior when    |[8/9/10 Regression]
                   |class defined with          |Unexpected behavior when
                   |namespace alias             |class defined with
                   |                            |namespace alias
     Ever confirmed|0                           |1
      Known to fail|                            |10.0, 8.3.0, 9.2.0

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Started to be rejected with r248095

            * cp-tree.h (SCOPE_DEPTH): New.
            * name-lookup.h (is_nested_namespace): Declare.
            * name-lookup.c (is_nested_namespace): New.
            (is_ancestor): Use it.
            (set_decl_namespace): Likewise.
            (push_namespace): Set SCOPE_DEPTH.
            * pt.c (check_specialization_namespace): Use is_nested_namespace.
            (check_unqualigied_spec_or_inst): Likewise.