provide a hook into the translation_url engine

My problem here is actually with taxonomy redirect: if I redirect a taxonomy/node/!termid to foo/!termid, translation_url() ignores the pattern and doesn't rewrite the url properly.

But to fix the issue, i need a patch to the translation.module.

External modules that modify URLs (in this case, taxonomy_redirect.module) should have a way to modify the translation_url (in translation.module) engine. I think this should be implemented as a hook (say hook_translation_url_modify()) that allows the $url to be modified in the translation_url() function.

I attach the language switching block i designed to workaround the issue for now.