Insert write command creates db and collection on invalid input

> use newdb

switched to db newdb

> db.dropDatabase()

{ "dropped" : "newdb", "ok" : 1 }

> db.stats()

{

        "db" : "newdb",

        "collections" : 0,

        "objects" : 0,

        "avgObjSize" : 0,

        "dataSize" : 0,

        "storageSize" : 0,

        "numExtents" : 0,

        "indexes" : 0,

        "indexSize" : 0,

        "fileSize" : 0,

        "dataFileVersion" : {

        },

        "ok" : 1

}

> db.getMongo().insert('newdb.foo', {$notAllowed: true}, 0);

> db.stats()

{

        "db" : "newdb",

        "collections" : 0,

        "objects" : 0,

        "avgObjSize" : 0,

        "dataSize" : 0,

        "storageSize" : 0,

        "numExtents" : 0,

        "indexes" : 0,

        "indexSize" : 0,

        "fileSize" : 0,

        "dataFileVersion" : {

        },

        "ok" : 1

}

> db.foo.runCommand('insert', {documents: [{$notAllowed: true}]})

{

        "ok" : 1,

        "n" : 0,

        "writeErrors" : [

                {

                        "index" : 0,

                        "code" : 2,

                        "errmsg" : "Document can't have $ prefixed field names: $notAllowed"

                }

        ]

}

> db.stats()

{

        "db" : "newdb",

        "collections" : 3,

        "objects" : 4,

        "avgObjSize" : 64,

        "dataSize" : 256,

        "storageSize" : 24576,

        "numExtents" : 3,

        "indexes" : 1,

        "indexSize" : 8176,

        "fileSize" : 67108864,

        "nsSizeMB" : 16,

        "dataFileVersion" : {

                "major" : 4,

                "minor" : 5

        },

        "extentFreeList" : {

                "num" : 0,

                "totalSize" : 0

        },

        "ok" : 1

}

> db.foo.stats()

{

        "ns" : "newdb.foo",

        "count" : 0,

        "size" : 0,

        "storageSize" : 8192,

        "numExtents" : 1,

        "nindexes" : 1,

        "lastExtentSize" : 8192,

        "paddingFactor" : 1,

        "systemFlags" : 1,

        "userFlags" : 1,

        "totalIndexSize" : 8176,

        "indexSizes" : {

                "_id_" : 8176

        },

        "ok" : 1

}