Reported on the swig-devel mailing list during early testing of swig-4.5,
where CrossWire SWORD's Perl bindings (GBFHTMLHREF::MyUserData deriving
from BasicFilterUserData) failed to build: a protected or private nested
class deriving from a class used elsewhere in the wrapped API could produce
a runtime upcast helper function referencing the nested class by its
inaccessible qualified name, a C++ compile error. No target language ever
wraps a non-public nested class, so typepass.cxx now simply skips
registering it for the cast table. Fixes it for Lua too, which hits the
same bug as Perl/Python/Ruby/Tcl despite having full nested class support,
since Java/C# are structurally immune (they don't use SWIG's generic
runtime type table at all). Added regression tests to nested_scope.i and
director_protected.i (covering directors/dirprot), with a runtime check in
every director_protected runme confirming polymorphic dispatch through the
wrapped base still works correctly.
Assisted-by: Claude Code (Sonnet 5)
William S Fulton