Fix a bug concerning record field types

The default value 'undefined' was added to records field types in such
a way that the result was not always a well-formed type. This bug has
been fixed.

---

erl_pp has since OTP-8150 formatted types so that 'undefined' was
removed from union types assigned to record fields. Since one cannot
distinguish between 'undefined' added by the parser or supplied by the
user, a side effect was that user supplied 'undefined's were also
removed.

Now the pretty printer shows 'undefined' even if added by the parser.
This is a minor issue.

1 files changed, 8 insertions, 2 deletions

diff --git a/lib/stdlib/src/erl_parse.yrl b/lib/stdlib/src/erl_parse.yrl
index bb4b18cf9b..15b45d72f4 100644
--- a/lib/stdlib/src/erl_parse.yrl
+++ b/lib/stdlib/src/erl_parse.yrl
@@ -2,7 +2,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -757,7 +757,8 @@ record_fields([{typed,Expr,TypeInfo}|Fields]) ->
 	    {atom, La, _} ->
                 case has_undefined(TypeInfo) of
                     false ->
-                        lift_unions(abstract(undefined, La), TypeInfo);
+                        TypeInfo2 = maybe_add_paren(TypeInfo),
+                        lift_unions(abstract(undefined, La), TypeInfo2);
                     true ->
                         TypeInfo
                 end
@@ -778,6 +779,11 @@ has_undefined({type,_,union,Ts}) ->
 has_undefined(_) ->
     false.
 
+maybe_add_paren({ann_type,L,T}) ->
+    {paren_type,L,[{ann_type,L,T}]};
+maybe_add_paren(T) ->
+    T.
+
 term(Expr) ->
     try normalise(Expr)
     catch _:_R -> ret_err(?line(Expr), "bad attribute")