session name: empty for Pure and by default;

--- a/src/Pure/Thy/present.ML	Mon Jun 23 19:00:24 2008 +0200
+++ b/src/Pure/Thy/present.ML	Mon Jun 23 20:00:58 2008 +0200
@@ -76,7 +76,7 @@
 structure BrowserInfoData = TheoryDataFun
 (
   type T = {name: string, session: string list, is_local: bool};
-  val empty = {name = Context.PureN, session = [], is_local = false}: T;
+  val empty = {name = "", session = [], is_local = false}: T;
   val copy = I;
   fun extend _ = empty;
   fun merge _ _ = empty;
@@ -86,8 +86,6 @@
 val get_info = BrowserInfoData.get;
 val session_name = #name o get_info;
 
-val _ = Context.>> (Context.map_theory (put_info {name = "", session = [], is_local = false}));
-
 
 
 (** graphs **)