In versions prior to 3.3.3, running repairDatabase on a new, different-cased database returns this error:
{
	"ok" : 0,
	"errmsg" : "db already exists with different case already have: [a] trying to create [A]",
	"code" : 13297
}
In 3.3.3+, the same command terminates the server:
2016-04-28T16:11:12.503-0400 F STORAGE [conn1] Unexpected exception encountered while reopening database after repair. 2016-04-28T16:11:12.503-0400 F - [conn1] terminate() called. An exception is active; attempting to gather more information 2016-04-28T16:11:12.560-0400 F - [conn1] DBException::toString(): 13297 db already exists with different case already have: [a] trying to create [A] Actual exception type: mongo::UserException
- is duplicated by
- 
                    SERVER-22434 Running repairDatabase on non-existing database creates an empty db folder on filesystem -         
- Closed
 
-         
- is related to
- 
                    SERVER-24563 Secondary crash when inserting document into db with different case -         
- Closed
 
-