fruitless bactracing of clearing the theme registry

Rebuilding the theme registry

we know to do this it has to call hook_theme()

gp "module_implements('theme'" .
./includes/theme.inc:516: foreach (module_implements('theme') as $module) {

That's in the function

<?php
function _theme_load_registry($theme, $base_theme = NULL, $theme_engine = NULL) {
  // Check the theme registry cache; if it exists, use it.
  $cache = cache_get("theme_registry:$theme->name", 'cache');
  if (isset($cache->data)) {
    $registry = $cache->data;
  }
  else {
    // If not, build one and cache it.
    $registry = _theme_build_registry($theme, $base_theme, $theme_engine);
   // Only persist this registry if all modules are loaded. This assures a
   // complete set of theme hooks.
    if (module_load_all(NULL)) {
      _theme_save_registry($theme, $registry);
    }
  }
  return $registry;
}
?>

gp _theme_load_registry .

./includes/theme.inc:141:function _drupal_theme_initialize($theme, $base_theme = array(), $registry_callback = '_theme_load_registry') {

… i guess it's called a lot, what really matters is the clearing the cache.