[Bug c++/122958] [13/14/15/16 Regression] internal compiler error: tree check: accessed elt 3 of 'tree_vec' with 2 elts in tsubst, at cp/pt.cc:16806

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122958

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2025-12-02
                 CC|                            |jason at gcc dot gnu.org
     Ever confirmed|0                           |1
      Known to work|                            |4.7.2
      Known to fail|                            |16.0, 4.8.1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The ICE started in 4.8.0 with:

commit 49bb4bbe90dff8b1cc71e08693ed24e00b0f648e [r0-117682-g49bb4bbe90dff8]
Author:     Jason Merrill
AuthorDate: Thu Jul 5 20:39:01 2012

    re PR c++/50852 (ICE: internal compiler error: in tsubst, at cp/pt.c:11030)

            PR c++/50852
            PR c++/53039
            * tree.c (strip_typedefs_expr): New.
            * cp-tree.h: Declare it.
            * pt.c (convert_template_argument, unify): Use it.
            * parser.c (cp_parser_template_declaration_after_export): Don't
call
            fixup_template_parms.

    From-SVN: r189298