Against a corrupted data set (next extent header pointing to invalid location):
> db.test.ensureIndex({a:1})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 1,
"ok" : 1
}
> db.test.ensureIndex({b:1})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 1,
"numIndexesAfter" : 1,
"ok" : 1
}
>
Seems like ok should not be set to 1 here