Resumable exceptions

[Patrick R. Michaud]

Here's a simple test for resumable exceptions that I'm trying
to get to work.  I'm probably coding/understanding something wrong, 
so any suggestions or pointers would be greatly appreciated.

    .sub main :main
        push_eh catcher
        'foo'()
        pop_eh
        say 'ok 4'
        .return ()
      catcher:
        .get_results ($P0, $S0)
        $P1 = $P0['retcont']
        $P1()
    .end
    
    .sub 'foo'
        say 'ok 1'
        $P0 = new 'Exception'
        throw $P0
        say 'ok 2'
        $P0 = new 'Exception'
        throw $P0
        say 'ok 3'
    .end

What I'm trying to do is to test the ability to resume after
exceptions thrown by C<foo>.  The C<main> sub above sets up
a handler to catch exceptions, then calls C<foo>.  The handler
simply resumes any exception that is caught.  The C<foo> sub
prints 'ok 1', throws an exception, prints 'ok 2', throws another
exception, and prints 'ok 3'.

I can resume the first exception but not the second:

    $ ./parrot x.pir
    ok 1
    ok 2
    No exception handler and no message
    current instr.: 'foo' pc 46 (x.pir:20)
    called from Sub 'main' pc 29 (x.pir:10)
    $

Suggestions and corrections to my code welcomed.

Pm