src/Pure/name.ML

--- a/src/Pure/name.ML	Fri Nov 19 23:48:07 2010 +0100
+++ b/src/Pure/name.ML	Sat Nov 20 00:53:26 2010 +0100
@@ -166,7 +166,7 @@
           if is_valid x then x :: xs
           else
             (case Symbol.decode x of
-              Symbol.Sym name => "_" :: explode name @ sep xs
+              Symbol.Sym name => "_" :: raw_explode name @ sep xs
             | _ => sep xs);
         fun upper_lower cs =
           if upper then nth_map 0 Symbol.to_ascii_upper cs