Add local markdown version

Cached markdown version is composed both from global and local
markdown version. This allows admins to bump version locally when
needed (e.g. when external URL is changed).

1 files changed, 22 insertions, 1 deletions

diff --git a/app/models/concerns/cache_markdown_field.rb b/app/models/concerns/cache_markdown_field.rb
index 5fa6f79bdaa..1a8570b80c3 100644
--- a/app/models/concerns/cache_markdown_field.rb
+++ b/app/models/concerns/cache_markdown_field.rb
@@ -115,7 +115,28 @@ module CacheMarkdownField
   end
 
   def latest_cached_markdown_version
-    CacheMarkdownField::CACHE_COMMONMARK_VERSION
+    @latest_cached_markdown_version ||= (CacheMarkdownField::CACHE_COMMONMARK_VERSION << 16) | local_version
+  end
+
+  def local_version
+    # because local_markdown_version is stored in application_settings which
+    # uses cached_markdown_version too, we check explicitly to avoid
+    # endless loop
+    return local_markdown_version if has_attribute?(:local_markdown_version)
+
+    settings = Gitlab::CurrentSettings.current_application_settings
+
+    # Following migrations are not properly isolated and
+    # use real models (by calling .ghost method), in these migrations
+    # local_markdown_version attribute doesn't exist yet, so we
+    # use a default value:
+    # db/migrate/20170825104051_migrate_issues_to_ghost_user.rb
+    # db/migrate/20171114150259_merge_requests_author_id_foreign_key.rb
+    if settings.respond_to?(:local_markdown_version)
+      settings.local_markdown_version
+    else
+      0
+    end
   end
 
   included do