1 files changed, 17 insertions, 7 deletions
diff --git a/app/services/merge_requests/merge_service.rb b/app/services/merge_requests/merge_service.rb
index 07cbd8f92a9..a110abf8256 100644
--- a/app/services/merge_requests/merge_service.rb
+++ b/app/services/merge_requests/merge_service.rb
@@ -11,16 +11,21 @@ module MergeRequests
     attr_reader :merge_request, :source
 
     def execute(merge_request)
+      if project.merge_requests_ff_only_enabled && !self.is_a?(FfMergeService)
+        FfMergeService.new(project, current_user, params).execute(merge_request)
+        return
+      end
+
       @merge_request = merge_request
 
       unless @merge_request.mergeable?
-        return log_merge_error('Merge request is not mergeable', save_message_on_model: true)
+        return handle_merge_error(log_message: 'Merge request is not mergeable', save_message_on_model: true)
       end
 
       @source = find_merge_source
 
       unless @source
-        return log_merge_error('No source for merge', save_message_on_model: true)
+        return handle_merge_error(log_message: 'No source for merge', save_message_on_model: true)
       end
 
       merge_request.in_locked_state do
@@ -31,8 +36,7 @@ module MergeRequests
         end
       end
     rescue MergeError => e
-      clean_merge_jid
-      log_merge_error(e.message, save_message_on_model: true)
+      handle_merge_error(log_message: e.message, save_message_on_model: true)
     end
 
     private
@@ -74,10 +78,16 @@ module MergeRequests
       @merge_request.force_remove_source_branch? ? @merge_request.author : current_user
     end
 
-    def log_merge_error(message, save_message_on_model: false)
-      Rails.logger.error("MergeService ERROR: #{merge_request_info} - #{message}")
+    # Logs merge error message and cleans `MergeRequest#merge_jid`.
+    #
+    def handle_merge_error(log_message:, save_message_on_model: false)
+      Rails.logger.error("MergeService ERROR: #{merge_request_info} - #{log_message}")
 
-      @merge_request.update(merge_error: message) if save_message_on_model
+      if save_message_on_model
+        @merge_request.update(merge_error: log_message, merge_jid: nil)
+      else
+        clean_merge_jid
+      end
     end
 
     def merge_request_info