I have a site collection with custom web parts (which do not alter permission groups but use them) and custom permission groups in Sharepoint 2013. There are no subsites.
When I add a user to a reader group I expect him to be able to access the home page. But he is unable. Neither directly to the page (http://siteColletion/Pages/home.aspx) nor from te redirect (http://siteCollection).
The pages library inherits permissions. There are no items that break permissions in this library.
The way I found the user is able to access the page is to make him join a collaborator group, enter http://siteColletion/Pages/home.aspx and then remove him from the group. Note that http://siteCollection at this time does not let the user access the site collection, but does after going through http://siteColletion/Pages/home.aspx.
Checking permissions before and after the process for the user returns the same groups and attached permissions.
The question is: What I have to do so I can add users directly to a reader group and have them being able to access the home page?
Note: The screen that shows when the user has no permissions is "Let us know why you need access to this site."
Cached user: Adding user once to a collaborator group and accessing the home page is enough to make him always able to access home while he is in a reader.
SuperCached user: Reseting IIS won't make the user unable to access again