[HttpFoundation] do not use server variable PATH_INFO because it is already decoded and thus symfony is fragile to double encoding of the path
merged branch Tobion/apache-pathinfo (PR #7656)

This PR was merged into the 2.1 branch.

Discussion
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[HttpFoundation] do not use server variable PATH_INFO

because it is already decoded (see http://www.ietf.org/rfc/rfc3875) and thus symfony is fragile to double encoding of the path. This is not really a security issue (in contrast to a [previous problem](http://symfony.com/blog/security-release-symfony-2-0-20-and-2-1-5-released)) but when using the apacherequest, one could access pages with double encoded characters although the path should not match.

BC break: no
tests pass: yes

Commits
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d552e4c [HttpFoundation] do not use server variable PATH_INFO because it is already decoded and thus symfony is fragile to double encoding of the path