Unfortunally, that may mean that the following code:

sub foo {
    my $i;
    for $i (...) {
       ...
       if (...) {
          my $i;
          $i = something;
          ...
       }
    }
}
[download]

may end up as:

sub foo {
    my $i;
    for $i (...) {
       ...
       if (...) {
          # my $i;
          $i = something;
          ...
       }
    }
}
[download]

However, the inner '$i' certainly wasn't an unused variable.