Search indexing disabled for pages with off-case restrictions

If you restrict viewing of a page to "Confluence-administrators" when the group is actually "confluence-administrators" (i.e. by manually entering the group name and hitting enter), no warning is displayed, but suddenly the page and all its children are no longer indexed.

I have verified the problem behavior with Confluence 2.9 and 2.10.3 with or without LDAP enabled.

Steps to reproduce:

1. Create a page which is restricted to an off-case group that the current user is a member of (such as "Confluence-administrators"). Include distinct content to aid in searching.
2. Rebuild the search indexing
3. Search for the new page

If there is a valid group or user permission (i.e. with the right case), the page is indexed. If there is only a page restriction with the wrong case, the page is not indexed.

The behaviour is the same when users are added to page restrictions with the wrong case.