Q:

Symfony 2.0 session locale not set from URL?

I'm creating a web page URL for an external application to access, like: http://my.site/en/page/1 or 
 http://my.site/fr/page/1. In Twig template, I'm using app.session.locale variable.
app.session.locale work fine, but url() and path() functions sometimes randomly use default locale - they generate /en/ URLs instead of /fr/ on a /fr/ page. This doesn't reproduce in a stable way. 
Adding _locale parameter like url('_foobar_action', {'something': model.fooId, '_locale': app.session.locale} ) doesn't help. This sounds like this discussion which is no good news.
There is no session in the external application that acessess this URL, it's safe to consider it to be wget.
What can be wrong here? Is it a known problem?

A:

There was a major change committed today in the master branch. You may want to check it out even though you're on 2.0. http://github.com/symfony/symfony/pull/4692

