Issue #11571: Ensure that the turtle window becomes the topmost window
when launched on OS X.  (Original patch by Ronald Oussoren)
diff --git a/Lib/turtle.py b/Lib/turtle.py
index ab7b6ba..599f645 100644
--- a/Lib/turtle.py
+++ b/Lib/turtle.py
@@ -109,6 +109,7 @@
 import math
 import time
 import inspect
+import sys
 
 from os.path import isfile, split, join
 from copy import deepcopy
@@ -992,6 +993,12 @@
         self._colormode = _CFG["colormode"]
         self._keys = []
         self.clear()
+        if sys.platform == 'darwin':
+            # Force Turtle window to the front on OS X. This is needed because
+            # the Turtle window will show behind the Terminal window when you
+            # start the demo from the command line.
+            cv._rootwindow.call('wm', 'attributes', '.', '-topmost', '1')
+            cv._rootwindow.call('wm', 'attributes', '.', '-topmost', '0')
 
     def clear(self):
         """Delete all drawings and all turtles from the TurtleScreen.
diff --git a/Misc/NEWS b/Misc/NEWS
index 1b5ac6c..5edfb04 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -168,6 +168,9 @@
 - Issue #21311: Avoid exception in _osx_support with non-standard compiler
   configurations.  Patch by John Szakmeister.
 
+- Issue #11571: Ensure that the turtle window becomes the topmost window
+  when launched on OS X.
+
 Extension Modules
 -----------------