Patch #1272, by Christian Heimes and Alexandre Vassalotti.
Changes to make __file__ a proper Unicode object, using the default
filesystem encoding.
This is a bit tricky because the default filesystem encoding isn't
set by the time we import the first modules; at that point we fudge
things a bit.  This is okay since __file__ isn't really used much
except for error reporting.
Tested on OSX and Linux only so far.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 55af338..647ea3e 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -5370,7 +5370,7 @@
 #endif
     if (name == NULL)
         return PyErr_NoMemory();
-    result = PyString_FromString(name);
+    result = PyUnicode_DecodeFSDefault(name);
     free(name);
     return result;
 }
@@ -5428,7 +5428,7 @@
 	Py_XDECREF(err);
 	return NULL;
     }
-    return PyString_FromString(buffer);
+    return PyUnicode_DecodeFSDefault(buffer);
 }
 #endif