#442

backend/app/models/history_access.rb

@@ -109,11 +109,15 @@ class HistoryAccess < ActiveSupport::CurrentAttributes
       # conservatively; never expose a private linked name through an external tag.
       names = "JSON_MERGE_PRESERVE(JSON_ARRAY(private_tag.name), " +
           "COALESCE(JSON_EXTRACT(private_tag.names, '$**.name'), JSON_ARRAY()))"
-      ["NOT EXISTS (SELECT 1 FROM tag_versions private_tag " +
+      # DISTINCT prevents merging this independent name set into the correlated scan.
+      # Keep byte-distinct names even when the column collation considers them equal.
+      private_names = 'SELECT DISTINCT private_name.name, ' +
+          'CAST(private_name.name AS BINARY) AS name_bytes FROM tag_versions private_tag ' +
           "JOIN (#{ discarded_keys('tag_versions', 'tag_id') }) blocked " +
           "ON blocked.tag_id = private_tag.tag_id " +
           "JOIN JSON_TABLE(#{ names }, '$[*]' COLUMNS (name TEXT PATH '$')) private_name " +
-          "WHERE private_name.name <> '' AND " +
+          "WHERE private_name.name <> ''"
+      ["NOT EXISTS (SELECT 1 FROM (#{ private_names }) private_name WHERE " +
           "LOCATE(CONCAT(' ', private_name.name, ' '), " +
           "CONCAT(' ', COALESCE(#{ row }.linked_tags, ''), ' ')) > 0)"]
     when 'tag_versions'