1.1 --- a/src/Pure/Isar/runtime.ML	Thu Jul 24 23:01:23 2014 +0200
     1.2 +++ b/src/Pure/Isar/runtime.ML	Thu Jul 24 23:18:01 2014 +0200
     1.3 @@ -166,10 +166,10 @@
     1.4  (*Proof General legacy*)
     1.5  fun thread interrupts body =
     1.6    Thread.fork
     1.7 -    (((fn () => body () handle exn => if Exn.is_interrupt exn then () else reraise exn)
     1.8 -        |> debugging NONE
     1.9 -        |> toplevel_error
    1.10 -          (fn exn => Output.urgent_message ("## INTERNAL ERROR ##\n" ^ exn_message exn))),
    1.11 +    (fn () =>
    1.12 +      debugging NONE body () handle exn =>
    1.13 +        if Exn.is_interrupt exn then ()
    1.14 +        else Output.urgent_message ("## INTERNAL ERROR ##\n" ^ exn_message exn),
    1.15        Simple_Thread.attributes interrupts);
    1.16  
    1.17  end;