Clicking on page or sitemenu link from angular dialog opens wrong channel in case channel has a non empty mountpath

Steps to reproduce:

1. start the archetype CMS
2. create a subsite called 'Test' with URL 'http://localhost/test'
3. open the 'Test' channel
4. click 'Pages'
5. click the first and only page '/' called 'root'

Expected: the home page of the 'Test' subsite is shown
Actual: the home page of the other channel is shown

Second reproduction path (with menus):

After step 1-3 described above:
4. click 'Edit Channel'
5. click 'Edit menu'
6. in the properties of the selected menu item 'home', click the browse-to icon right of the internal link 'home'

Expected: the home page of the Test subsite is shown
Actual: the home page of the other channel is shown