1 files changed, 20 insertions, 0 deletions
diff --git a/test/ruby/test_signal.rb b/test/ruby/test_signal.rb
index b8a20d945c..425dc26574 100644
--- a/test/ruby/test_signal.rb
+++ b/test/ruby/test_signal.rb
@@ -369,4 +369,24 @@ class TestSignal < Test::Unit::TestCase
   ensure
     trap(:CHLD, old) if Signal.list['CHLD']
   end
+
+  def test_sigwait_fd_unused
+    t = EnvUtil.apply_timeout_scale(0.1)
+    assert_separately([], <<-End)
+      tgt = $$
+      trap(:TERM) { exit(0) }
+      e = "Process.daemon; sleep #{t * 2}; Process.kill(:TERM,\#{tgt})"
+      term = [ '#{EnvUtil.rubybin}', '--disable=gems', '-e', e ]
+      t2 = Thread.new { sleep } # grab sigwait_fd
+      Thread.pass until t2.stop?
+      Thread.new do
+        sleep #{t}
+        t2.kill
+        t2.join
+      end
+      Process.spawn(*term)
+      # last thread remaining, ensure it can react to SIGTERM
+      loop { sleep }
+    End
+  end if Process.respond_to?(:kill) && Process.respond_to?(:daemon)
 end