I may be missing something but am thinking that the test below points out a bug, but I maybe be missing something

set up collection:-
db.test.save({ "_id" : "IBM.N|00001264779918428889", "DESCRIPTION" :

{ "n" : "IBM STK2", "o" : "IBM STK", "s" : "changed" }

}
db.test.save({ "_id" : "VOD.N|00001264779918433344", "COMPANYNAME" :

{ "n" : "Vodafone Group PLC 2", "o" : "Vodafone Group PLC", "s" : "changed" }

})
db.test.save({ "_id" : "IBM.N|00001264779918437075", "DESCRIPTION" :

{ "n" : "IBM STK3", "o" : "IBM STK2", "s" : "changed" }

})
db.test.save({ "_id" : "VOD.N|00001264779918441426", "COMPANYNAME" :

{ "n" : "Vodafone Group PLC 3", "o" : "Vodafone Group PLC 2", "s" : "changed" }

})

I am expecting that

db.test.find().min(

{"_id":"IBM.N|00000000000000000000"}

).max(

{"_id":"IBM.N|99999999999999999999"}

);

should return
{ "_id" : "IBM.N|00001264779918428889", "DESCRIPTION" :

{ "n" : "IBM STK2", "o" : "IBM STK", "s" : "changed" }

}
{ "_id" : "IBM.N|00001264779918437075", "DESCRIPTION" :

{ "n" : "IBM STK3", "o" : "IBM STK2", "s" : "changed" }

}

and not

error: { "$err" : "no index found for specified keyPattern: {}" }