Fix `Thread#join(timeout)` when running inside the fiber scheduler. (#7903)

1 files changed, 22 insertions, 0 deletions

diff --git a/test/fiber/test_thread.rb b/test/fiber/test_thread.rb
index 5c25c43de2..6fae266955 100644
--- a/test/fiber/test_thread.rb
+++ b/test/fiber/test_thread.rb
@@ -20,6 +20,28 @@ class TestFiberThread < Test::Unit::TestCase
     assert_equal :done, thread.value
   end
 
+  def test_thread_join_timeout
+    sleeper = nil
+
+    thread = Thread.new do
+      scheduler = Scheduler.new
+      Fiber.set_scheduler scheduler
+
+      Fiber.schedule do
+        sleeper = Thread.new{sleep}
+        sleeper.join(0.1)
+      end
+
+      scheduler.run
+    end
+
+    thread.join
+
+    assert_predicate sleeper, :alive?
+  ensure
+    sleeper&.kill
+  end
+
   def test_thread_join_implicit
     sleeping = false
     finished = false