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/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
index a1a0e0d..385add4 100644
--- a/Modules/_ctypes/callbacks.c
+++ b/Modules/_ctypes/callbacks.c
@@ -34,9 +34,9 @@
 	PyCodeObject *py_code = 0;
 	PyFrameObject *py_frame = 0;
     
-	py_srcfile = PyString_FromString(filename);
+	py_srcfile = PyUnicode_DecodeFSDefault(filename);
 	if (!py_srcfile) goto bad;
-	py_funcname = PyString_FromString(funcname);
+	py_funcname = PyUnicode_FromString(funcname);
 	if (!py_funcname) goto bad;
 	py_globals = PyDict_New();
 	if (!py_globals) goto bad;
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
 
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 6cfb8ec..ae6f143 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -232,13 +232,13 @@
         code = PyString_FromString("");
         if (code == NULL)
             goto failed;
-        name = PyString_FromString(func_name);
+        name = PyUnicode_FromString(func_name);
         if (name == NULL)
             goto failed;
         nulltuple = PyTuple_New(0);
         if (nulltuple == NULL)
             goto failed;
-        filename = PyString_FromString(__FILE__);
+        filename = PyUnicode_DecodeFSDefault(__FILE__);
         handler_info[slot].tb_code =
             PyCode_New(0,		/* argcount */
                        0,       /* kwonlyargcount */