If no beam locations found for an image, dont treat this as an error,…

… simply return no beams. Also multiquant was failing to overwrite zstack because it wasn't defined as an upsert

api/ws/handlers/image-beam-location.go

@@ -60,7 +60,10 @@ func HandleImageBeamLocationsReq(req *protos.ImageBeamLocationsReq, hctx wsHelpe
 		result := coll.FindOne(ctx, bson.M{"_id": req.ImageName})
 		if result.Err() != nil {
 			if result.Err() == mongo.ErrNoDocuments {
-				return nil, errorwithstatus.MakeNotFoundError(req.ImageName)
+				// If there are no beam locations, don't return an error, just return a message with no items in it
+				return &protos.ImageBeamLocationsResp{
+					Locations: &protos.ImageLocations{ImageName: req.ImageName},
+				}, nil
 			}
 			return nil, result.Err()
 		}

api/ws/handlers/quantification-multi.go

@@ -11,6 +11,7 @@ import (
 	protos "github.com/pixlise/core/v4/generated-protos"
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
 )
 
 // Anyone can retrieve a quant z-stack if they have quant messaging permissions
@@ -65,13 +66,15 @@ func HandleQuantCombineListWriteReq(req *protos.QuantCombineListWriteReq, hctx w
 		List:   req.List,
 	}
 
-	result, err := coll.InsertOne(ctx, doc)
+	opt := options.Update().SetUpsert(true)
+
+	result, err := coll.UpdateByID(ctx, zId, bson.D{{Key: "$set", Value: doc}}, opt)
 	if err != nil {
 		return nil, err
 	}
 
-	if result.InsertedID != zId {
-		hctx.Svcs.Log.Errorf("MultiQuant Z-Stack insert %v inserted different id %v", zId, result.InsertedID)
+	if result.UpsertedCount != 1 {
+		hctx.Svcs.Log.Errorf("MultiQuant Z-Stack write for: %v got unexpected DB write result: %+v", req.ScanId, result)
 	}
 
 	return &protos.QuantCombineListWriteResp{}, nil