"multiple" numeric zero fields not preserved upon edit

Scenario:

You have a numeric field in your content-type, and this field is marked as "Multiple values". You enter some values into it, e.g. the three values 7, 0, 9. You save the node.

You now call up this node for editing, and you discover that the zero is missing. Only 7 and 9 appear in the form.

This is because of the textfield building code in 'number.module':

      if ($field['multiple']) {
        $form[$field['field_name']]['#type'] = 'fieldset';
        $form[$field['field_name']]['#title'] = t($field['widget']['label']);
        $delta = 0;
        foreach ($node_field as $data) {
HERE--->  if ($data['value']) {
            $form[$field['field_name']][$delta]['value'] = array(
              '#type' => 'textfield',
              '#title' => '',
              '#default_value' => $data['value'],
              '#required' => ($delta == 0) ? $field['required'] : FALSE,
              '#maxlength' => 11,
            );
            $delta++;
          }
        }

if problem is the conditional if ($data['value']). When the field's value is zero, the corresponding textfield is not generated.