use strict;
use warnings;
use Imager;

use Inline with => 'Imager';
use Inline C => << 'END_OF_C';

void _replace( Imager img, SV* str ) {
    unsigned char* ptr = SvPV_nolen( str );
    myfree( img-> idata );
    img-> idata = ptr;
}

END_OF_C

my $i = Imager-> new( xsize => 99, ysize => 99 );

for ( 'A' .. 'F' ) {
    print "$_\n";
    my $s;
    $i-> write( data => \$s, type => 'raw' );
    my $j = $i-> copy();
    
# Here, it's rumored, some nasty things 
# happening, that involve $j and $s.
# But maybe nothing happens.
    
    _replace( $i, $s );
}

__END__

~$ perl test.pl
A
B
*** Error in `perl': double free or corruption (!prev): 0x0000000002d67990 ***
Aborted (core dumped)