RequestCacheThreadLocalFilter is not applied to /qunit resources

RequestCacheThreadLocal holds a per-request "cache" that is used, in particular, by Crowd's implementation of WebResourceIntegration (and in turn, by WebResourceManager and SoyTemplateRenderer).

This cache is initialized and cleaned-up in RequestCacheThreadLocalFilter. This filter is mapped to a number of patterns, including /plugins/servlet/*. However, it is mapped only for the REQUEST dispatcher.

Our problem in our plugin is when using the QUnit plugin: it uses URL rewriting so you can access it using /qunit, which is not covered by the mapping. It eventually ends up forwarding the request to /plugin/servlet/something but since the mapping does not apply to the FORWARD dispatcher, the filter is never applied.

Other problem: RequestCacheThreadLocal defines an initial value. However:

• it is also initialized in the filter, which is redundant
• the clean-up code sets the thread local value to null, instead of calling remove()