Check if head_pipeline is correct before merging

1 files changed, 8 insertions, 4 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index b9158d3c863..536ad05a43d 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -145,8 +145,11 @@ class MergeRequest < ActiveRecord::Base
     '!'
   end
 
-  def head_pipeline
-    super&.sha == diff_head_sha ? super : nil
+  # Use this method whenever you need to make sure the head_pipeline is synced with the
+  # branch head commit, for example checking if a merge request can be merged.
+  # For more information check: https://gitlab.com/gitlab-org/gitlab-ce/issues/40004
+  def current_head_pipeline
+    head_pipeline&.sha == diff_head_sha ? head_pipeline : nil
   end
 
   # Pattern used to extract `!123` merge request references from text
@@ -826,8 +829,9 @@ class MergeRequest < ActiveRecord::Base
 
   def mergeable_ci_state?
     return true unless project.only_allow_merge_if_pipeline_succeeds?
+    return true unless head_pipeline
 
-    !head_pipeline || head_pipeline.success? || head_pipeline.skipped?
+    current_head_pipeline&.success? || current_head_pipeline&.skipped?
   end
 
   def environments_for(current_user)
@@ -1001,7 +1005,7 @@ class MergeRequest < ActiveRecord::Base
     return true if autocomplete_precheck
 
     return false unless mergeable?(skip_ci_check: true)
-    return false if head_pipeline && !(head_pipeline.success? || head_pipeline.active?)
+    return false if current_head_pipeline && !(current_head_pipeline.success? || current_head_pipeline.active?)
     return false if last_diff_sha != diff_head_sha
 
     true