Symfony getter overloading

Company.php

<?php

/**
 * Company
 *
 * This class has been auto-generated by the Doctrine ORM Framework
 *
 * @package    winston
 * @subpackage model
 * @author     Clement Herreman <clement@activcompany.fr>
 * @version    SVN: $Id$
 */
class Company extends BaseCompany
{
  /**
   * Return the Company logo. If none, return the placeholder.
   */
  public function getLogo()
  {
    if ($this->hasLogo())
      return parent::_get('logo');
    else
      return sfConfig::get('app_company_logo_placeholder');
  }

  /**
   * Tells if this Company has a Logo.
   * @return bool True if this Company has a logo, else false.
   */
  public function hasLogo()
  {
    $logo = parent::_get('logo');
    
    //Todo : check if $logo is a readable file
    return !empty($logo);
  }

  public function save(Doctrine_Connection $conn = null)
  {
    if ( $this->hasLogo())
    {
      //Here some code where I crop the logo, deleted for easy debugging.

      //ERREUR : at fixtures loading : 
      //SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'company_id' cannot be null
    }

  }
}

schema.yml

Company:
  actAs:
    Sluggable:
      fields:         [name]
      unique:         true
    Timestampable:
      updated:        { disabled: true }
  columns:
    name:             { type: string(255), notnull: true }
    logo:             { type: string }
  relations:
    Campaigns:
      type:           many
      class:          Campaign
      local:          id
      foreign:        company_id
      onDelete:       cascade
    Profiles:
      type:           many
      class:          sfGuardUserProfile
      local:          id
      foreign:        company_id
      onDelete:       cascade
    Functionnalities:
      class:          Functionnality
      local:          functionnality_id
      foreign:        company_id
      refClass:       Subscription
      foreignAlias:   Companies
    DefaultMediaSources:
      class:          MediaSource
      local:          id
      foreign:        company_id
      refClass:       CompanyMediaSource
      foreignAlias:   Companies

Remark : I checked my fixtures twice, and even when I keep only the Company fixtures, I still get an exception.
It only stop crashing when I delete the $this->hasLogo() in the save() method

For those interested in : the exception can be avoided by replacing $this->_get('logo'); with parent::_get('logo');
See gist.

Thank you @n1k0 !