Do not autosplat when calling proc with empty keyword splat

With the removal of the splatted argument when using an empty
keyword splat, the autosplat code considered an empty keyword
splat the same as no argument at all.  However, that results
in autosplat behavior changing dependent on the content of
the splatted hash, which is not what anyone would expect or
want.  This change always skips an autosplat if keywords were
provided.

Fixes [Bug #16560]

1 files changed, 20 insertions, 0 deletions

diff --git a/test/ruby/test_proc.rb b/test/ruby/test_proc.rb
index af4cf11623..4177707ddd 100644
--- a/test/ruby/test_proc.rb
+++ b/test/ruby/test_proc.rb
@@ -1087,6 +1087,26 @@ class TestProc < Test::Unit::TestCase
     assert_equal([1,2,[3],4,5], r, "[ruby-core:19485]")
   end
 
+  def test_proc_autosplat
+    def self.a(arg, kw)
+      yield arg
+      yield arg, **kw
+      yield arg, kw
+    end
+
+    arr = []
+    a([1,2,3], {}) do |arg1, arg2=0|
+      arr << [arg1, arg2]
+    end
+    assert_equal([[1, 2], [[1, 2, 3], 0], [[1, 2, 3], {}]], arr)
+
+    arr = []
+    a([1,2,3], a: 1) do |arg1, arg2=0|
+      arr << [arg1, arg2]
+    end
+    assert_equal([[1, 2], [[1, 2, 3], {a: 1}], [[1, 2, 3], {a: 1}]], arr)
+  end
+
   def test_proc_single_arg_with_keywords_accepted_and_yielded
     def self.a
       yield [], **{a: 1}