I get no output when I run this:

use strict;
sub open {
  my $filehandle = shift;
  return CORE::open($filehandle,@_[0..$#_]);
}

my $file = $0;
my $AFILE;
if (main::open ($AFILE, '<', $file)) {
  print while <$AFILE>;
}
else {
  warn 'Failed';
}
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(I do get output if the condition in the if statement is

main::open($AFILE = IO::File->new(), "<$file")
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)