Synchronize the default branch when updating a remote mirror

3 files changed, 10 insertions, 2 deletions

diff --git a/app/models/project.rb b/app/models/project.rb
index 45cf527d7c6..8928bffd36c 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -2063,6 +2063,12 @@ class Project < ActiveRecord::Base
     auto_cancel_pending_pipelines == 'enabled'
   end
 
+  # Update the default branch querying the remote to determine its HEAD
+  def update_root_ref(remote_name)
+    root_ref = repository.find_remote_root_ref(remote_name)
+    change_head(root_ref) if root_ref.present? && root_ref != default_branch
+  end
+
   private
 
   def rename_or_migrate_repository!
diff --git a/app/models/repository.rb b/app/models/repository.rb
index 929d28b9d88..e98021af818 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -24,6 +24,7 @@ class Repository
 
   delegate :ref_name_for_sha, to: :raw_repository
   delegate :bundle_to_disk, to: :raw_repository
+  delegate :find_remote_root_ref, to: :raw_repository
 
   CreateTreeError = Class.new(StandardError)
 
diff --git a/app/services/projects/update_remote_mirror_service.rb b/app/services/projects/update_remote_mirror_service.rb
index 591b38b8151..85b9eb02803 100644
--- a/app/services/projects/update_remote_mirror_service.rb
+++ b/app/services/projects/update_remote_mirror_service.rb
@@ -5,13 +5,14 @@ module Projects
     attr_reader :errors
 
     def execute(remote_mirror)
-      @errors = []
-
       return success unless remote_mirror.enabled?
 
+      errors = []
+
       begin
         remote_mirror.ensure_remote!
         repository.fetch_remote(remote_mirror.remote_name, no_tags: true)
+        project.update_root_ref(remote_mirror.remote_name)
 
         opts = {}
         if remote_mirror.only_protected_branches?