[perl #39135] Problem with concat on Match objects

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# New Ticket Created by  Patrick R. Michaud 
# Please include the string:  [perl #39135]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/rt3/Ticket/Display.html?id=39135 >


I've run into the following problem using concat with
Match objects from PGE.  The code below performs a match,
then attempts to concatenate a string with the results
of the returned Match object:

    $ cat y.pir
    .sub main :main
        load_bytecode 'PGE.pbc'
    
        $P0 = compreg 'PGE::P6Regex'
        $P1 = $P0('.+')
        $P2 = $P1('world')
    
        say $P2              # world
    
        $P3 = new .String
        $P3 = 'hello '
    
        $P4 = new .String
        $P4 = concat $P3, $P2
        say $P4              # hello world
    .end
    
    $ ./parrot y.pir
    world
    Null PMC access in clone()
    current instr.: 'main' pc 42 (y.pir:14)
    $

The returned match object (in $P2) works fine if cast to a
string (see the "say $P2" line above), but for some reason 
the concat operation results in a "NULL PMC access" error.

I'm also entering a todo test for the above into t/compilers/pge/02-match.t.

Thanks,

Pm