symfony creates unexpected page cache when requested by HEAD method.

kris did you plan on working on this for 1.2.9? I was about to release it, so I unset the milestone.

This has been addressed in the 1.3 branch.

This is a workaround for those using 1.2.

- lib/headCacheFilter.class.php

<?php

/**
 * Disable the cache for HEAD requests
 */
class headCacheFilter extends sfFilter
{
    public function execute($filterChain)
    {
        $context = $this->getContext();

        if($context->getRequest()->getMethod() == sfWebRequest::HEAD) {
            sfConfig::set('sf_cache', false);
        }

        // Execute next filter
        $filterChain->execute();
    }
}

- filters.yml

rendering: ~
security:  ~

head_cache_filter:
  class: headCacheFilter

cache:     ~
common:    ~
execution: ~

It took me quite a while to determine for sure that this was a bug with symfony as this post doesn't rank well in search engines. Basically if you start getting blank pages in your app and you have caching turned on for actions, including the layout, it's probably as a result of this bug.

I'm not sure what is sending HEAD requests so often, possibly web crawlers.