The API lists duplicate protection entries when both page.page_restrictions and page_protections.* entries are present. This can currently be seen on the Wikipedia "Main page" redirect:

http://en.wikipedia.org/w/api.php?action=query&titles=Main+page&prop=info&inprop=protection

While the correct action is probably to run whatever maintenance script is necessary to resolve the anomaly between tables, the API should probably also account for the possibility that this script has never been run.

Version: 1.23.0
Severity: minor