fix vote and questionanswer deletion

app/controllers/VoteController.java

@@ -47,13 +47,13 @@ public class VoteController extends Controller {
 				// session owner has the power to reset all
 				for (Vote v : session.votes) {
 					if (v.type == Vote.Type.REQUEST && v.owner == vote.owner || vote.owner == session.owner) {
-						v.delete();
+						session.deleteVote(v);
 					}
 				}
 			} else {
 				session.addVote(inserted);
-				session.save();
 			}
+			session.save();
 			return created(Json.toJson(inserted)); // 201
 		} else {
 			return badRequest("owner missing"); // 400

app/models/Session.java

@@ -42,7 +42,6 @@ public class Session extends Model {
 
 	@JsonIgnore
 	@OneToMany(mappedBy = "session", cascade = CascadeType.ALL)
-	@Column(nullable = true)
 	public List<Vote> votes = new ArrayList<Vote>();
 
 	@Formats.DateTime(pattern = "yyyy-MM-dd HH:mm:ss")
@@ -86,6 +85,12 @@ public class Session extends Model {
 		for (QuestionAnswer a : this.questionAnswers) {
 			a.delete();
 		}
+		this.questionAnswers.clear();
+	}
+
+	public void deleteVote(Vote v) {
+		v.delete();
+		this.votes.remove(v);
 	}
 
 	public void addVote(Vote v) {

app/models/Vote.java

@@ -8,13 +8,13 @@ import javax.persistence.Entity;
 import javax.persistence.Id;
 import javax.persistence.ManyToOne;
 
+import com.avaje.ebean.annotation.EnumValue;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
 import play.data.format.Formats;
 import play.data.validation.Constraints;
 import play.db.ebean.Model;
 
-import com.avaje.ebean.annotation.EnumValue;
-import com.fasterxml.jackson.annotation.JsonIgnore;
-
 @Entity
 public class Vote extends Model {