Issue #28746: Fix the set_inheritable() file descriptor method on platforms

that do not have the ioctl FIOCLEX and FIONCLEX commands

Misc/NEWS

@@ -10,6 +10,9 @@ What's New in Python 3.6.0 beta 4
 Core and Builtins
 -----------------
 
+- Issue #28746: Fix the set_inheritable() file descriptor method on platforms
+  that do not have the ioctl FIOCLEX and FIONCLEX commands.
+
 - Issue #26920: Fix not getting the locale's charset upon initializing the
   interpreter, on platforms that do not have langinfo.
 

Python/fileutils.c

@@ -886,7 +886,7 @@ set_inheritable(int fd, int inheritable, int raise, int *atomic_flag_works)
         return 0;
     }
 
-    res = fcntl(fd, F_SETFD, flags);
+    res = fcntl(fd, F_SETFD, new_flags);
     if (res < 0) {
         if (raise)
             PyErr_SetFromErrno(PyExc_OSError);