Fully separate positional arguments and keyword arguments

This removes the warnings added in 2.7, and changes the behavior
so that a final positional hash is not treated as keywords or
vice-versa.

To handle the arg_setup_block splat case correctly with keyword
arguments, we need to check if we are taking a keyword hash.
That case didn't have a test, but it affects real-world code,
so add a test for it.

This removes rb_empty_keyword_given_p() and related code, as
that is not needed in Ruby 3.  The empty keyword case is the
same as the no keyword case in Ruby 3.

This changes rb_scan_args to implement keyword argument
separation for C functions when the : character is used.
For backwards compatibility, it returns a duped hash.
This is a bad idea for performance, but not duping the hash
breaks at least Enumerator::ArithmeticSequence#inspect.

Instead of having RB_PASS_CALLED_KEYWORDS be a number,
simplify the code by just making it be rb_keyword_given_p().

1 files changed, 1 insertions, 3 deletions

diff --git a/object.c b/object.c
index b5514322d2..f02b45af1c 100644
--- a/object.c
+++ b/object.c
@@ -4086,9 +4086,7 @@ rb_obj_dig(int argc, VALUE *argv, VALUE obj, VALUE notfound)
 	}
         return rb_check_funcall_with_hook_kw(obj, id_dig, argc, argv,
                                           no_dig_method, obj,
-                                          rb_empty_keyword_given_p() ?
-                                            RB_PASS_EMPTY_KEYWORDS :
-                                            RB_NO_KEYWORDS);
+                                          RB_NO_KEYWORDS);
     }
     return obj;
 }