Does tha capture object $/ retain a live tie to the string it matched?

[Carl Mäsak]

Yesterday I got bitten by the fact that currently in Rakudo, $/
doesn't copy content from the matched string, but instead trusts that
it stays in the matched string and doesn't change.

Is this the intended behaviour, or should $/ keep a copy the string
contents? As the following examples show, Im hoping for the latter.

 # should $/ really keep ties to $s like this?
<masak> rakudo: my $s = "hello"; $s ~~ /hello/; $s = "goodbye"; say $/
<p6eval> rakudo 29834: OUTPUT[goodb␤]

 # I mean, it's not only unintuitive, it's dangerous, too
<masak> rakudo: my $s = "abcdefg"; $s ~~ /efg/; $s = "abc"; say $/
<p6eval> rakudo 29834: OUTPUT[Cannot take substr outside
string␤current instr.: 'parrot;PGE::Match;text' pc 328
(compilers/pge/PGE/Match.pir:220)␤]

# this is how I discovered this behaviour. action at a distance!
<masak> rakudo: my $t = 'ABC'; $t ~~ /(A)B(C)/; $t = $0; my $u = $1;
<p6eval> rakudo 29834: OUTPUT[Cannot take substr outside
string␤current instr.: 'parrot;PGE::Match;text' pc 328
(compilers/pge/PGE/Match.pir:220)␤]

# the fact that there's such a method as .orig gives me some hope that
# the above is not the intended behaviour. however, as you see, $/.orig
# is not implemented in rakudo.
<masak> rakudo: my $s = "hello"; $s ~~ /ello/; say $/.orig
<p6eval> rakudo 29834: OUTPUT[Method 'orig' not found for invocant of
class  'PGE::Match'␤current instr.: '_block11' pc 60 (EVAL_14:24)␤]

S05:2377:

The currently defined methods are

    $/.from     # the initial match position
    $/.to       # the final match position
    $/.chars    # $/.to - $/.from
    $/.orig     # the original match string
    $/.text     # substr($/.orig, $/.from, $/.chars)