Comment 1 for bug 1311584

Verified with pt-table-sync 2.2.9,

nilnandan@nilnandan-Dell-XPS:~$ pt-table-sync --version
pt-table-sync 2.2.9
nilnandan@nilnandan-Dell-XPS:~$

~line 10510:

# Determine which columns to compare.
      my $ignore_columns = $o->get('ignore-columns');
      my @compare_columns = grep {
         !$ignore_columns->{lc $_};
      } @{$o->get('columns') || $tbl_struct->{cols}};