> The code is inside a loop (yes it is) so there is no need to use goto:

Are you sure? IMHO each redo means leaving the scope and "delocalizes" all variables so far.

perl -e '
NEXT: {
  local $a.=$x++;
  redo NEXT if $x<10;
  print $a;             # prints only 9
}
'
[download]

BTW: no need for a NEXT label, redo alone would do! : )

UPDATE: I think you're wrong!

$x=0;
{
 NEXT: 
 { 
  $x==0 ? (local $a="A") : (local $b="B");
  redo NEXT if $x++<1;
  print $a,$b;             
 }
}
[download]

only prints "B"! BUT

$x=0;
{
 NEXT: 
  $x==0 ? (local $a="A") : (local $b="B");
  goto NEXT if $x++<1;
  print $a,$b;             
}
[download]

prints "AB"