1 files changed, 25 insertions, 4 deletions
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 628c61d5d69..9c4384a6e42 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -104,24 +104,35 @@ class MergeRequest < ActiveRecord::Base
 
   state_machine :merge_status, initial: :unchecked do
     event :mark_as_unchecked do
-      transition [:can_be_merged, :cannot_be_merged] => :unchecked
+      transition [:can_be_merged, :unchecked] => :unchecked
+      transition [:cannot_be_merged, :cannot_be_merged_recheck] => :cannot_be_merged_recheck
     end
 
     event :mark_as_mergeable do
-      transition [:unchecked, :cannot_be_merged] => :can_be_merged
+      transition [:unchecked, :cannot_be_merged_recheck] => :can_be_merged
     end
 
     event :mark_as_unmergeable do
-      transition [:unchecked, :can_be_merged] => :cannot_be_merged
+      transition [:unchecked, :cannot_be_merged_recheck] => :cannot_be_merged
     end
 
     state :unchecked
+    state :cannot_be_merged_recheck
     state :can_be_merged
     state :cannot_be_merged
 
     around_transition do |merge_request, transition, block|
       Gitlab::Timeless.timeless(merge_request, &block)
     end
+
+    after_transition unchecked: :cannot_be_merged do |merge_request, transition|
+      NotificationService.new.merge_request_unmergeable(merge_request)
+      TodoService.new.merge_request_became_unmergeable(merge_request)
+    end
+
+    def check_state?(merge_status)
+      [:unchecked, :cannot_be_merged_recheck].include?(merge_status.to_sym)
+    end
   end
 
   validates :source_project, presence: true, unless: [:allow_broken, :importing?, :closed_without_fork?]
@@ -327,6 +338,16 @@ class MergeRequest < ActiveRecord::Base
     update_column(:merge_jid, jid)
   end
 
+  def merge_participants
+    participants = [author]
+
+    if merge_when_pipeline_succeeds? && !participants.include?(merge_user)
+      participants << merge_user
+    end
+
+    participants
+  end
+
   def first_commit
     merge_request_diff ? merge_request_diff.first_commit : compare_commits.first
   end
@@ -602,7 +623,7 @@ class MergeRequest < ActiveRecord::Base
   end
 
   def check_if_can_be_merged
-    return unless unchecked? && Gitlab::Database.read_write?
+    return unless self.class.state_machines[:merge_status].check_state?(merge_status) && Gitlab::Database.read_write?
 
     can_be_merged =
       !broken? && project.repository.can_be_merged?(diff_head_sha, target_branch)