Issue Summary

Normally Confluence doesn't let create group names by using upper-case. However, this check doesn't apply when the group names are synchronized from an LDAP server. So the group names with all upper-case or mixed upper-case and lower-case are allowed to be synchronized from LDAP servers.

When setting page restrictions via the below REST API for the group names with mixed upper-case and lower-case, these pages can be viewed by the member of these groups, however, they are not searchable through the search section.

REST API:
<confluence-base-url>/rest/experimental/content/<pageId>/restriction

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. Set up Confluence with an AD.
2. Create a group with a fix of upper and lower case names (e.g. AbCd) or generally have uppercase characters.
3. Create a page.
4. Use the REST API to update the page restrictions with the group name.

   <confluence-base-url>/rest/experimental/content/<pageId>/restriction
   
   [
       {
           "operation": "update",
           "restrictions": {
               "group": [],
               "user": [
                   {
                       "type": "user",
                       "username": "admin"
                   }
               ]
           },
           "operation": "read",
           "restrictions": {
               "user": [
                   {
                       "type": "user",
                       "username": "admin"
                   }
               ],
               "group": [
                   {
                       "type": "group",
                       "name": "AbCd"
                   }
               ]
           }
       }
   ]
   

Expected Results

The related restricted pages should be both viewable and searchable by the member of the groups that contain a mix of upper-case and lower-case characters. 

Actual Results

The related restricted pages are viewable but they are not searchable by the member of the groups that contain a mix of upper-case and lower-case characters. 

Workaround

Using Confluence UI to restrict the pages for the related groups instead of REST API.