Just show the first merge request we found, feedback:

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6019#note_16963209

app/mailers/emails/pipelines.rb

@@ -13,7 +13,7 @@ module Emails
     def pipeline_mail(pipeline, to, status)
       @project = pipeline.project
       @pipeline = pipeline
-      @merge_request = pipeline.merge_requests_with_active_first.first
+      @merge_request = pipeline.merge_requests.first
       add_headers
 
       mail(to: to, subject: pipeline_subject(status), skip_premailer: true) do |format|

app/models/ci/pipeline.rb

@@ -302,12 +302,6 @@ module Ci
         .select { |merge_request| merge_request.pipeline.try(:id) == self.id }
     end
 
-    def merge_requests_with_active_first
-      merge_requests.sort_by do |merge_request|
-        [merge_request.state_priority, -merge_request.updated_at.to_i]
-      end
-    end
-
     private
 
     def pipeline_data

app/models/merge_request.rb

@@ -169,10 +169,6 @@ class MergeRequest < ActiveRecord::Base
     work_in_progress?(title) ? title : "WIP: #{title}"
   end
 
-  def state_priority
-    %w[opened reopened closed merged locked].index(state)
-  end
-
   def to_reference(from_project = nil)
     reference = "#{self.class.reference_prefix}#{iid}"
 

spec/models/ci/pipeline_spec.rb

@@ -523,35 +523,4 @@ describe Ci::Pipeline, models: true do
       expect(pipeline.merge_requests).to be_empty
     end
   end
-
-  describe '#merge_requests_with_active_first' do
-    let(:project) { create(:project) }
-
-    let(:pipeline) do
-      create(:ci_empty_pipeline,
-             status: 'created',
-             project: project,
-             ref: 'master',
-             sha: project.repository.commit('master').sha)
-    end
-
-    let!(:merge_requests) do
-      [create_merge_request(:merged, Time.at(0)),
-       create_merge_request(:merged, Time.at(9)),
-       create_merge_request(:opened, Time.at(0))]
-    end
-
-    it 'returns opened/recent merge requests first, then closed ones' do
-      expect(pipeline.merge_requests_with_active_first).
-        to eq(merge_requests.reverse)
-    end
-
-    def create_merge_request(state, updated_at)
-      create(:merge_request,
-             source_project: project,
-             source_branch: pipeline.ref,
-             state: state,
-             updated_at: updated_at)
-    end
-  end
 end

spec/models/merge_request_spec.rb

@@ -58,14 +58,6 @@ describe MergeRequest, models: true do
     it { is_expected.to respond_to(:merge_when_build_succeeds) }
   end
 
-  describe '#state_priority' do
-    it 'returns the priority of state' do
-      %w[opened reopened closed merged locked].each.with_index do |state, idx|
-        expect(MergeRequest.new(state: state).state_priority).to eq(idx)
-      end
-    end
-  end
-
   describe '.in_projects' do
     it 'returns the merge requests for a set of projects' do
       expect(described_class.in_projects(Project.all)).to eq([subject])