Preloads head pipeline for each merge request

3 files changed, 10 insertions, 8 deletions

diff --git a/app/controllers/concerns/issuable_collections.rb b/app/controllers/concerns/issuable_collections.rb
index 6df2c068745..650ec1e326a 100644
--- a/app/controllers/concerns/issuable_collections.rb
+++ b/app/controllers/concerns/issuable_collections.rb
@@ -47,7 +47,7 @@ module IssuableCollections
   end
 
   def merge_requests_collection
-    merge_requests_finder.execute.preload(:source_project, :target_project, :author, :assignee, :labels, :milestone, :merge_request_diff, target_project: :namespace)
+    merge_requests_finder.execute.preload(:source_project, :target_project, :author, :assignee, :labels, :milestone, :merge_request_diff, :head_pipeline, target_project: :namespace)
   end
 
   def issues_finder
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 35231bab12e..3a2cff6ac21 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -13,6 +13,8 @@ class MergeRequest < ActiveRecord::Base
   has_one :merge_request_diff,
     -> { order('merge_request_diffs.id DESC') }
 
+  belongs_to :head_pipeline, foreign_key: "head_pipeline_id", class_name: "Ci::Pipeline"
+
   has_many :events, as: :target, dependent: :destroy
 
   has_many :merge_requests_closing_issues, class_name: 'MergeRequestsClosingIssues', dependent: :delete_all
@@ -829,12 +831,6 @@ class MergeRequest < ActiveRecord::Base
     diverged_commits_count > 0
   end
 
-  def head_pipeline
-    return unless diff_head_sha && source_project
-
-    @head_pipeline ||= source_project.pipeline_for(source_branch, diff_head_sha)
-  end
-
   def all_pipelines
     return Ci::Pipeline.none unless source_project
 
diff --git a/app/services/ci/create_pipeline_service.rb b/app/services/ci/create_pipeline_service.rb
index ccdda08d885..26b744ae3c4 100644
--- a/app/services/ci/create_pipeline_service.rb
+++ b/app/services/ci/create_pipeline_service.rb
@@ -47,7 +47,7 @@ module Ci
       end
 
       Ci::Pipeline.transaction do
-        pipeline.save
+        update_merge_requests_head_pipeline if pipeline.save
 
         Ci::CreatePipelineBuildsService
           .new(project, current_user)
@@ -118,6 +118,12 @@ module Ci
       origin_sha && origin_sha != Gitlab::Git::BLANK_SHA
     end
 
+    def update_merge_requests_head_pipeline
+      merge_requests = MergeRequest.where(source_branch: @pipeline.ref, source_project: @pipeline.project)
+
+      merge_requests.update_all(head_pipeline_id: @pipeline.id) if merge_requests.any?
+    end
+
     def error(message, save: false)
       pipeline.errors.add(:base, message)
       pipeline.drop if save