From b43214c533ae5942ec4b50c9f32e749b8ca5daae Mon Sep 17 00:00:00 2001
From: Timothy Andrew <mail@timothyandrew.net>
Date: Tue, 20 Sep 2016 10:45:36 +0530
Subject: [PATCH] Add a uniqueness constraint to `MergeRequestsClosingIssues`

---
 app/models/merge_requests_closing_issues.rb | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/app/models/merge_requests_closing_issues.rb b/app/models/merge_requests_closing_issues.rb
index 4f093fa27c5..cd49076002d 100644
--- a/app/models/merge_requests_closing_issues.rb
+++ b/app/models/merge_requests_closing_issues.rb
@@ -1,4 +1,9 @@
 class MergeRequestsClosingIssues < ActiveRecord::Base
   belongs_to :merge_request
   belongs_to :issue
+
+  validates_uniqueness_of :merge_request_id, scope: :issue_id
+
+  validates_presence_of :merge_request
+  validates_presence_of :issue
 end