diff -r cc15d736d860 Python/pylifecycle.c
--- a/Python/pylifecycle.c	Mon Aug 24 20:31:53 2015 -0700
+++ b/Python/pylifecycle.c	Fri Sep 04 15:37:08 2015 +0200
@@ -1,4 +1,3 @@
-
 /* Python interpreter top-level routines, including init/exit */
 
 #include "Python.h"
@@ -963,6 +962,21 @@
     }
 }
 
+static int
+is_valid_fd(int fd)
+{
+    int dummy_fd;
+    if (fd < 0 || !_PyVerify_fd(fd))
+        return 0;
+    _Py_BEGIN_SUPPRESS_IPH
+        dummy_fd = dup(fd);
+    if (dummy_fd >= 0)
+        close(dummy_fd);
+    _Py_END_SUPPRESS_IPH
+        return dummy_fd >= 0;
+}
+
+/* returns Py_None if the fd is not valid */
 static PyObject*
 create_stdio(PyObject* io,
     int fd, int write_mode, char* name,
@@ -1059,21 +1073,18 @@
     Py_XDECREF(stream);
     Py_XDECREF(text);
     Py_XDECREF(raw);
-    return NULL;
-}
-
-static int
-is_valid_fd(int fd)
-{
-    int dummy_fd;
-    if (fd < 0 || !_PyVerify_fd(fd))
-        return 0;
-    _Py_BEGIN_SUPPRESS_IPH
-    dummy_fd = dup(fd);
-    if (dummy_fd >= 0)
-        close(dummy_fd);
-    _Py_END_SUPPRESS_IPH
-    return dummy_fd >= 0;
+    if (!is_valid_fd(fd)) {
+        /* Python has to remain alive even when one stdio fd is invalid.
+         * This check is moved *after* all the function calls on the fd
+         *  to avoid race conditions (e.g. fd gets closed after the check).
+         *  See #24891 and #7111 for details.
+         */
+        PyErr_Clear();
+        stream = Py_None;
+        Py_INCREF(stream);
+        return stream;
+    } else
+        return NULL;
 }
 
 /* Initialize sys.stdin, stdout, stderr and builtins.open */
@@ -1158,30 +1169,18 @@
      * and fileno() may point to an invalid file descriptor. For example
      * GUI apps don't have valid standard streams by default.
      */
-    if (!is_valid_fd(fd)) {
-        std = Py_None;
-        Py_INCREF(std);
-    }
-    else {
-        std = create_stdio(iomod, fd, 0, "<stdin>", encoding, errors);
-        if (std == NULL)
-            goto error;
-    } /* if (fd < 0) */
+    std = create_stdio(iomod, fd, 0, "<stdin>", encoding, errors);
+    if (std == NULL)
+        goto error;
     PySys_SetObject("__stdin__", std);
     _PySys_SetObjectId(&PyId_stdin, std);
     Py_DECREF(std);
 
     /* Set sys.stdout */
     fd = fileno(stdout);
-    if (!is_valid_fd(fd)) {
-        std = Py_None;
-        Py_INCREF(std);
-    }
-    else {
-        std = create_stdio(iomod, fd, 1, "<stdout>", encoding, errors);
-        if (std == NULL)
-            goto error;
-    } /* if (fd < 0) */
+    std = create_stdio(iomod, fd, 1, "<stdout>", encoding, errors);
+    if (std == NULL)
+        goto error;
     PySys_SetObject("__stdout__", std);
     _PySys_SetObjectId(&PyId_stdout, std);
     Py_DECREF(std);
@@ -1189,15 +1188,9 @@
 #if 1 /* Disable this if you have trouble debugging bootstrap stuff */
     /* Set sys.stderr, replaces the preliminary stderr */
     fd = fileno(stderr);
-    if (!is_valid_fd(fd)) {
-        std = Py_None;
-        Py_INCREF(std);
-    }
-    else {
-        std = create_stdio(iomod, fd, 1, "<stderr>", encoding, "backslashreplace");
-        if (std == NULL)
-            goto error;
-    } /* if (fd < 0) */
+    std = create_stdio(iomod, fd, 1, "<stderr>", encoding, "backslashreplace");
+    if (std == NULL)
+        goto error;
 
     /* Same as hack above, pre-import stderr's codec to avoid recursion
        when import.c tries to write to stderr in verbose mode. */