Adding changesets from branch is broken when specific priviledges apply to repos

I just noticed the following bug when I tried to add a changeset from a branch.

Steps to reproduce:

• add a repository A, limit the access to the repository to a group G
• create a project P, add A to P and make A the default repository of P when creating reviews
• add a repository B, do not limit the access
• create a review in P with a user U not in the restricted group G
• add a changeset from a branch: we have then an internal error because the user U does not have access to the default repository A, which is the one shown by default

Expected behaviour:

• when adding a changeset from a branch, the repositories that should be shown are the ones to which the current user has access to, not the default of the project.