From 877effc2986ad30ecd5454811b0449bcfe3037f5 Mon Sep 17 00:00:00 2001
From: Hynek Schlawack <hs@ox.cx>
Date: Fri, 25 May 2012 09:24:18 +0200
Subject: [PATCH] #4841: Fix FileIO constructor to honor closefd when called
 repeatedly

Patch by Victor Stinner.
---
 Lib/test/test_io.py  | 13 +++++++++++++
 Modules/_io/fileio.c | 10 +++++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index b9972f3ac5..72feff59e4 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -593,6 +593,19 @@ class IOTest(unittest.TestCase):
         self.assertEqual(rawio.read(2), None)
         self.assertEqual(rawio.read(2), b"")
 
+    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):
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 0048240b79..d1941dfa74 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -198,9 +198,13 @@ fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)
 
     assert(PyFileIO_Check(oself));
     if (self->fd >= 0) {
-        /* Have to close the existing file first. */
-        if (internal_close(self) < 0)
-            return -1;
+        if (self->closefd) {
+            /* Have to close the existing file first. */
+            if (internal_close(self) < 0)
+                return -1;
+        }
+        else
+            self->fd = -1;
     }
 
     if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|si:fileio",
-- 
2.50.0