$display_submitted unavailable on node.tpl.php

variable $display_submitted is unavailble at node.tpl.php and avoiding exibition control from the theme.

despite this the variable $display_submitted is available at template.php and arriving empty on node.tpl.php.

To make work, I did:

# template.php 
<?php

function novoportal_preprocess_node(&$variables) {
    $variables['display_submitted_by'] = $variables['display_submitted'];
}

?>

Just copy $variables['display_submitted']; to preserve it from something that cleans up.

# templates/note.tpl.php 
    <?php
      hide($content['comments']);
      hide($content['links']);
      hide($content['submitted_by']);
      print render($content);
    ?>
[...]
      <?php if ($display_submitted_by): ?>
           <?php print render($content['submitted_by']); ?>
      <?php endif; ?>
[...]

$display_submitted is unavailable here!