Merge branch 'master' into fix_mac_shlibversion_gh_issue_3241

src/CHANGES.txt

@@ -64,6 +64,9 @@ RELEASE 3.1.0.alpha.yyyymmdd - NEW DATE WILL BE INSERTED HERE
       Note that the values of the above will be validated. Valid format for either APPLELINK variable is
       X[.Y[.Z]] where 0 <= X <= 65535, 0 <= Y <= 255, 0 <= Z <= 255.
       The new variables have been added to the documents and should show up in user guide and manpage.
+    - Fix GH Issue #3136 no longer wrap io.{BufferedReader,BufferedWriter,BufferedRWPair,BufferedRandom,TextIOWrapper
+      with logic to set HANDLE_FLAG_INHERIT flag on the file handle.  Python 3.4+ automatically sets this according
+      to Python docs: https://docs.python.org/3/library/os.html#fd-inheritance
 
   From Andrew Featherstone
     - Removed unused --warn options from the man page and source code.

src/engine/SCons/Platform/win32.py

@@ -82,16 +82,8 @@ def __init__(self, *args, **kw):
                  win32con.HANDLE_FLAG_INHERIT, 0)
         file = _scons_file
     else:
-        import io
-        for io_class in ['BufferedReader', 'BufferedWriter', 'BufferedRWPair',
-                         'BufferedRandom', 'TextIOWrapper']:
-            _builtin_file = getattr(io, io_class)
-            class _scons_file(_builtin_file):
-                def __init__(self, *args, **kw):
-                    _builtin_file.__init__(self, *args, **kw)
-                    win32api.SetHandleInformation(msvcrt.get_osfhandle(self.fileno()),
-                        win32con.HANDLE_FLAG_INHERIT, 0)
-            setattr(io, io_class, _scons_file)
+        # No longer needed for python 3.4 and above. Files are opened non sharable
+        pass