text: s = new ShardingTest( "auto1" , 2 , 1 , 1 );
  
  s.adminCommand( { enablesharding : "test" } );
  s.adminCommand( { shardcollection : "test.update1" , key : { key : 1 } } );
  
  db = s.getDB( "test" )
  coll = db.update1;
  
  coll.insert({_id:1, key:1});
  
  // these are both upserts
  coll.save({_id:2, key:2});
  coll.update({_id:3, key:3}, {$set: {foo: 'bar'}}, {upsert: true});
  
  assert.eq(coll.count(), 3, "count A")
  assert.eq(coll.findOne({_id:3}).key, 3 , "findOne 3 key A")
  assert.eq(coll.findOne({_id:3}).foo, 'bar' , "findOne 3 foo A")
  
  // update existing using save()
  coll.save({_id:1, key:1, other:1});
  
  // update existing using update()
  coll.update({_id:2}, {key:2, other:2});
  coll.update({_id:3}, {key:3, other:3});
  
  coll.update({_id:3, key:3}, {other:4});
  assert.eq(db.getLastErrorObj().code, 12376, 'bad update error');
  
  assert.eq(coll.count(), 3, "count B")
  coll.find().forEach(function(x){
      assert.eq(x._id, x.key, "_id == key");
      assert.eq(x._id, x.other, "_id == other");
  });
  
  
  coll.update({_id:1, key:1}, {$set: {key:2}});
  err = db.getLastErrorObj();
  assert.eq(coll.findOne({_id:1}).key, 1, 'key unchanged');
  assert.eq(err.code, 13123, 'key error code 1');
  assert.eq(err.code, 13123, 'key error code 2');
  
  coll.update({_id:1, key:1}, {$set: {foo:2}});
  assert.isnull(db.getLastError(), 'getLastError reset');
  
  s.stop()
  
  