Index: Lib/doctest.py
===================================================================
--- Lib/doctest.py	(revision 83356)
+++ Lib/doctest.py	(working copy)
@@ -239,6 +239,16 @@
 class _SpoofOut(StringIO):
     def getvalue(self):
         result = StringIO.getvalue(self)
+        if isinstance(self.buf, unicode):
+            # The doctest text file paths will be 8bit.
+            # Thus any Unicode in the buffer needs to be converted
+            # to 8bit before the values in self.buflist are
+            # added to self.buf.
+            self.buf = self.buf.encode(sys.getfilesystemencoding())
+        if self.buflist:
+            self.buf += ''.join(self.buflist)
+            self.buflist = []
+        result = self.buf
         # If anything at all was written, make sure there's a trailing
         # newline.  There's no way for the expected output to indicate
         # that a trailing newline is missing.