Revert "Automatically update MR merge-ref along merge status"

1 files changed, 21 insertions, 15 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 4fcaac75655..7481f1939ad 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -725,16 +725,19 @@ class MergeRequest < ApplicationRecord
 
     MergeRequests::ReloadDiffsService.new(self, current_user).execute
   end
-
-  def check_mergeability
-    MergeRequests::MergeabilityCheckService.new(self).execute
-  end
   # rubocop: enable CodeReuse/ServiceClass
 
-  # Returns boolean indicating the merge_status should be rechecked in order to
-  # switch to either can_be_merged or cannot_be_merged.
-  def recheck_merge_status?
-    self.class.state_machines[:merge_status].check_state?(merge_status)
+  def check_if_can_be_merged
+    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)
+
+    if can_be_merged
+      mark_as_mergeable
+    else
+      mark_as_unmergeable
+    end
   end
 
   def merge_event
@@ -760,7 +763,7 @@ class MergeRequest < ApplicationRecord
   def mergeable?(skip_ci_check: false)
     return false unless mergeable_state?(skip_ci_check: skip_ci_check)
 
-    check_mergeability
+    check_if_can_be_merged
 
     can_be_merged? && !should_be_rebased?
   end
@@ -775,6 +778,15 @@ class MergeRequest < ApplicationRecord
     true
   end
 
+  def mergeable_to_ref?
+    return false unless mergeable_state?(skip_ci_check: true, skip_discussions_check: true)
+
+    # Given the `merge_ref_path` will have the same
+    # state the `target_branch` would have. Ideally
+    # we need to check if it can be merged to it.
+    project.repository.can_be_merged?(diff_head_sha, target_branch)
+  end
+
   def ff_merge_possible?
     project.repository.ancestor?(target_branch_sha, diff_head_sha)
   end
@@ -1087,12 +1099,6 @@ class MergeRequest < ApplicationRecord
     target_project.repository.fetch_source_branch!(source_project.repository, source_branch, ref_path)
   end
 
-  # Returns the current merge-ref HEAD commit.
-  #
-  def merge_ref_head
-    project.repository.commit(merge_ref_path)
-  end
-
   def ref_path
     "refs/#{Repository::REF_MERGE_REQUEST}/#{iid}/head"
   end