3 files changed, 18 insertions, 1 deletions
diff --git a/test/ruby/test_thread.rb b/test/ruby/test_thread.rb
index 97643947ad..c1f03c7868 100644
--- a/test/ruby/test_thread.rb
+++ b/test/ruby/test_thread.rb
@@ -1104,4 +1104,14 @@ q.pop
     c = Class.new(Thread) {def initialize() self.name = "foo"; super; end}
     assert_equal("foo", c.new {Thread.current.name}.value)
   end
+
+  def test_thread_interrupt_for_killed_thread
+    assert_normal_exit(<<-_end, '[Bug #8996]', timeout: 5, timeout_error: nil)
+      trap(:TERM){exit}
+      while true
+        t = Thread.new{sleep 0}
+        t.raise Interrupt
+      end
+    _end
+  end
 end
diff --git a/thread.c b/thread.c
index 3ec4b900a7..473b6b686c 100644
--- a/thread.c
+++ b/thread.c
@@ -2090,6 +2090,13 @@ rb_threadptr_raise(rb_thread_t *th, int argc, VALUE *argv)
     else {
 	exc = rb_make_exception(argc, argv);
     }
+
+    /* making an exception object can switch thread,
+       so we need to check thread deadness again */
+    if (rb_threadptr_dead(th)) {
+	return Qnil;
+    }
+
     rb_threadptr_setup_exception(GET_THREAD(), exc, Qundef);
     rb_threadptr_pending_interrupt_enque(th, exc);
     rb_threadptr_interrupt(th);
diff --git a/version.h b/version.h
index 0628afac17..9ceb38e246 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.3.3"
 #define RUBY_RELEASE_DATE "2017-03-20"
-#define RUBY_PATCHLEVEL 248
+#define RUBY_PATCHLEVEL 249
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 3