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/Python/traceback.c b/Python/traceback.c
index 5bb8841..9d7a2e0 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -229,10 +229,10 @@
 	while (tb != NULL && err == 0) {
 		if (depth <= limit) {
 			err = tb_displayline(f,
-			    PyString_AsString(
+			    PyUnicode_AsString(
 				    tb->tb_frame->f_code->co_filename),
 			    tb->tb_lineno,
-			    PyString_AsString(tb->tb_frame->f_code->co_name));
+			    PyUnicode_AsString(tb->tb_frame->f_code->co_name));
 		}
 		depth--;
 		tb = tb->tb_next;