Fix evaluation order of hash values for duplicate keys

Fixes [Bug #17719]

Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
Co-authored-by: Ivo Anjo <ivo@ivoanjo.me>

1 files changed, 11 insertions, 0 deletions

diff --git a/test/ruby/test_literal.rb b/test/ruby/test_literal.rb
index 3a8ff7857f..8c3256c034 100644
--- a/test/ruby/test_literal.rb
+++ b/test/ruby/test_literal.rb
@@ -474,6 +474,17 @@ class TestRubyLiteral < Test::Unit::TestCase
     assert_nil(h['c'])
     assert_equal(nil, h.key('300'))
 
+    a = []
+    h = EnvUtil.suppress_warning do
+      eval <<~end
+        # This is a syntax that renders warning at very early stage.
+        # eval used to delay warning, to be suppressible by EnvUtil.
+        {"a" => a.push(100).last, "b" => a.push(200).last, "a" => a.push(300).last, "a" => a.push(400).last}
+      end
+    end
+    assert_equal({'a' => 400, 'b' => 200}, h)
+    assert_equal([100, 200, 300, 400], a)
+
     assert_all_assertions_foreach(
       "duplicated literal key",
       ':foo',