https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122509
--- Comment #7 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Jason Merrill <[email protected]>: https://gcc.gnu.org/g:d19b95ca96f2e10732007d9cd59e6430df8d0b2a commit r16-6274-gd19b95ca96f2e10732007d9cd59e6430df8d0b2a Author: Egas Ribeiro <[email protected]> Date: Sat Dec 13 20:06:09 2025 +0000 c++: Fix injected-class-name lookup with multiple bases [PR122509] When looking up an unqualified injected-class-name in a member access expression (e.g., D().v<int>), cp_parser_lookup_name calls lookup_member with protect=0, causing it to return NULL on ambiguity instead of the candidate list. This prevented the existing DR 176 logic in maybe_get_template_decl_from_type_decl from resolving the ambiguity. Per DR 176, if all ambiguous candidates are instantiations of the same class template and the name is followed by a template-argument-list, the reference is to the template itself and is not ambiguous. Fix by using protect=2 to return the ambiguous candidate list. PR c++/122509 gcc/cp/ChangeLog: * parser.cc (cp_parser_lookup_name): Use protect=2 instead of protect=0 when calling lookup_member. gcc/testsuite/ChangeLog: * g++.dg/tc1/dr176-2.C: New test. Signed-off-by: Egas Ribeiro <[email protected]> Reviewed-by: Jason Merrill <[email protected]>
