1 files changed, 9 insertions, 0 deletions
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index dcb81cfc6d..a916781fe8 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -169,6 +169,15 @@ CODE
     assert_raise(ArgumentError) { "foo"[] }
   end
 
+  def test_AREF_underflow
+    require "rbconfig/sizeof"
+    assert_equal(nil, S("\u{3042 3044 3046}")[RbConfig::LIMITS["LONG_MIN"], 1])
+  end
+
+  def test_AREF_invalid_encoding
+    assert_equal(S("\x80"), S("A"*39+"\x80")[-1, 1])
+  end
+
   def test_ASET # '[]='
     s = S("FooBar")
     s[0] = S('A')