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, 4 insertions, 6 deletions

diff --git a/thread.c b/thread.c
index 16f3e1ffed..4faf04c1ce 100644
--- a/thread.c
+++ b/thread.c
@@ -681,7 +681,6 @@ thread_do_start(rb_thread_t *th)
     if (th->invoke_type == thread_invoke_type_proc) {
         VALUE args = th->invoke_arg.proc.args;
         int args_len = (int)RARRAY_LEN(args);
-        int kw_splat = th->invoke_arg.proc.kw_splat;
         const VALUE *args_ptr;
         VALUE procval = th->invoke_arg.proc.proc;
 	rb_proc_t *proc;
@@ -704,10 +703,11 @@ thread_do_start(rb_thread_t *th)
             args_ptr = RARRAY_CONST_PTR(args);
         }
 
-        rb_adjust_argv_kw_splat(&args_len, &args_ptr, &kw_splat);
+        vm_check_ints_blocking(th->ec);
         th->value = rb_vm_invoke_proc(th->ec, proc,
                                       args_len, args_ptr,
-                                      kw_splat, VM_BLOCK_HANDLER_NONE);
+                                      th->invoke_arg.proc.kw_splat,
+                                      VM_BLOCK_HANDLER_NONE);
 
         EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_THREAD_END, th->self, 0, 0, 0, Qundef);
     }
@@ -856,9 +856,7 @@ thread_create_core(VALUE thval, VALUE args, VALUE (*fn)(void *))
         th->invoke_type = thread_invoke_type_proc;
         th->invoke_arg.proc.proc = rb_block_proc();
         th->invoke_arg.proc.args = args;
-        th->invoke_arg.proc.kw_splat = rb_empty_keyword_given_p() ?
-                                            RB_PASS_EMPTY_KEYWORDS :
-                                            rb_keyword_given_p();
+        th->invoke_arg.proc.kw_splat = rb_keyword_given_p();
     }
 
     th->priority = current_th->priority;