1 files changed, 16 insertions, 0 deletions
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index 149c128ed4..dcb81cfc6d 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -2010,6 +2010,22 @@ CODE
     assert_nil($&)
   end
 
+  def test_start_with_timeout_memory_leak
+    assert_no_memory_leak([], "#{<<~"begin;"}", "#{<<~'end;'}", "[Bug #20653]", rss: true)
+      regex = Regexp.new("^#{"(a*)" * 10_000}x$", timeout: 0.000001)
+      str = "a" * 1_000_000 + "x"
+
+      code = proc do
+        str.start_with?(regex)
+      rescue
+      end
+
+      10.times(&code)
+    begin;
+      1_000.times(&code)
+    end;
+  end
+
   def test_strip
     assert_equal(S("x"), S("      x        ").strip)
     assert_equal(S("x"), S(" \n\r\t     x  \t\r\n\n      ").strip)