Issues with hook_preprocess

I just found an issue while subtheming related to the code from the Studio theme & the hook_preprocess implementation that calls files from the preprocess directory.

Tested in a dev sandbox, this code seems to now work properly.

/**
 * Implementation of hook_preprocess()
 * 
 * This function checks to see if a hook has a preprocess file associated with 
 * it, and if so, loads it.
 * 
 * @param $vars
 * @param $hook
 * @return Array
 */
function canvas_preprocess(&$vars, $hook) {
  // Collect all information for the active theme.
  $themes_active = array();
  global $theme_info;

  // If there is a base theme, collect the names of all themes that may have 
  // preprocess files to load.
  if($theme_info->base_theme) {
    global $base_theme_info;
    foreach($base_theme_info as $base){
      $themes_active[] = $base->name;
    }
  }

  // Add the active theme to the list of themes that may have preprocess files.
  $themes_active[] = $theme_info->name;

  // Check all active themes for preprocess files that will need to be loaded.
  foreach($themes_active as $name) {
    if(is_file(drupal_get_path('theme', $name) . '/preprocess/preprocess-' . str_replace('_', '-', $hook) . '.inc')) {
      include(drupal_get_path('theme', $name) . '/preprocess/preprocess-' . str_replace('_', '-', $hook) . '.inc');
    }
  }
}

I will be testing this on my core development sandbox tomorrow, and patching if it works.
This was found causing issues in hook_preprocess node on a subtheme where it was only getting called once on pages with multiple nodes. The attributes being assigned by the default preprocess functionality in the Omega theme.

Solution was found here: http://cvs.drupal.org/viewvc.py/drupal/contributions/themes/studio/canvas/template.php?revision=1.3&view=markup