1 files changed, 13 insertions, 0 deletions
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 96258b4..f5bb732 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -643,6 +643,19 @@ class IOTest(unittest.TestCase):
         with self.open("non-existent", "r", opener=opener) as f:
             self.assertEqual(f.read(), "egg\n")
 
+    def test_fileio_closefd(self):
+        # Issue #4841
+        with self.open(__file__, 'rb') as f1, \
+             self.open(__file__, 'rb') as f2:
+            fileio = self.FileIO(f1.fileno(), closefd=False)
+            # .__init__() must not close f1
+            fileio.__init__(f2.fileno(), closefd=False)
+            f1.readline()
+            # .close() must not close f2
+            fileio.close()
+            f2.readline()
+
+
 class CIOTest(IOTest):
 
     def test_IOBase_finalize(self):