merge revision(s) fc33559c: [Backport #20570]

	clear `kw_flag` if given hash is nil

	https://bugs.ruby-lang.org/issues/20570 is caused I missed to
	clear the `kw_flag` even if `keyword_hash` is nil.

1 files changed, 18 insertions, 0 deletions

diff --git a/test/ruby/test_keyword.rb b/test/ruby/test_keyword.rb
index 9aca787dff..bc816751fd 100644
--- a/test/ruby/test_keyword.rb
+++ b/test/ruby/test_keyword.rb
@@ -4432,6 +4432,24 @@ class TestKeywordArgumentsSymProcRefinements < Test::Unit::TestCase
     assert_equal({one: 1, two: 2}, f.call(one:, two:))
   end
 
+  def m_bug20570(*a, **nil)
+    a
+  end
+
+  def test_splat_arg_with_prohibited_keyword
+    assert_equal([], m_bug20570(*[]))
+    assert_equal([1], m_bug20570(*[1]))
+    assert_equal([1, 2], m_bug20570(*[1, 2]))
+    h = nil
+    assert_equal([], m_bug20570(*[], **h))
+    assert_equal([1], m_bug20570(*[1], **h))
+    assert_equal([1, 2], m_bug20570(*[1, 2], **h))
+
+    assert_equal([], m_bug20570(*[], **nil))
+    assert_equal([1], m_bug20570(*[1], **nil))
+    assert_equal([1, 2], m_bug20570(*[1, 2], **nil))
+  end
+
   private def one
     1
   end