Wait on parent if poll() does not return an exit code

This handles the shutdown race in FFPuppet.wait() as well.

src/ffpuppet/core.py

@@ -958,7 +958,10 @@ def wait(self, timeout: Optional[float] = None) -> bool:
             True if processes exit before timeout expires otherwise False.
         """
         assert timeout is None or timeout >= 0
-        if not wait_procs(list(self.get_processes()), timeout=timeout)[1]:
+        procs = list(self.get_processes())
+        if not procs and self._proc and self._proc.poll() is None:
+            procs = [Process(self._proc.pid)]
+        if not wait_procs(procs, timeout=timeout)[1]:
             return True
         LOG.debug("wait(timeout=%0.2f) timed out", timeout)
         return False

src/ffpuppet/test_ffpuppet.py

@@ -194,9 +194,11 @@ def test_ffpuppet_06(mocker):
     class StubbedProc(FFPuppet):
         # pylint: disable=arguments-differ
         def close(self, **_):
+            self._proc = None
             self.reason = Reason.CLOSED
 
         def launch(self):
+            self._proc = mocker.Mock(spec=Popen, pid=os.getpid())
             self.reason = None
 
         def get_pid(self):
@@ -206,9 +208,14 @@ def get_pid(self):
 
     fake_wait_procs = mocker.patch("ffpuppet.core.wait_procs", autospec=True)
     with StubbedProc() as ffp:
+        ffp.launch()
         # process not running
         fake_wait_procs.return_value = ([], [])
-        ffp.launch()
+        assert ffp.wait()
+        assert fake_wait_procs.call_count == 1
+        fake_wait_procs.reset_mock()
+        # process is shutting down
+        ffp._proc.poll.return_value = None
         assert ffp.wait()
         assert fake_wait_procs.call_count == 1
         fake_wait_procs.reset_mock()