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

2 files changed, 19 insertions, 7 deletions

diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index f8b950cb55d..880b07d0a84 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -701,7 +701,7 @@ module API
       # See https://gitlab.com/gitlab-org/gitlab-ce/issues/42344 for more
       # information.
       expose :merge_status do |merge_request|
-        merge_request.check_mergeability
+        merge_request.check_if_can_be_merged
         merge_request.merge_status
       end
       expose :diff_head_sha, as: :sha
diff --git a/lib/api/merge_requests.rb b/lib/api/merge_requests.rb
index 5bbf6df78b0..955624404f1 100644
--- a/lib/api/merge_requests.rb
+++ b/lib/api/merge_requests.rb
@@ -397,16 +397,28 @@ module API
         present merge_request, with: Entities::MergeRequest, current_user: current_user, project: user_project
       end
 
-      desc 'Returns the up to date merge-ref HEAD commit'
-      get ':id/merge_requests/:merge_request_iid/merge_ref' do
+      desc 'Merge a merge request to its default temporary merge ref path'
+      params do
+        optional :merge_commit_message, type: String, desc: 'Custom merge commit message'
+      end
+      put ':id/merge_requests/:merge_request_iid/merge_to_ref' do
         merge_request = find_project_merge_request(params[:merge_request_iid])
 
-        result = ::MergeRequests::MergeabilityCheckService.new(merge_request).execute
+        authorize! :admin_merge_request, user_project
+
+        merge_params = {
+          commit_message: params[:merge_commit_message]
+        }
+
+        result = ::MergeRequests::MergeToRefService
+          .new(merge_request.target_project, current_user, merge_params)
+          .execute(merge_request)
 
-        if result.success?
-          present :commit_id, result.payload.dig(:merge_ref_head, :commit_id)
+        if result[:status] == :success
+          present result.slice(:commit_id), 200
         else
-          render_api_error!(result.message, 400)
+          http_status = result[:http_status] || 400
+          render_api_error!(result[:message], http_status)
         end
       end