Scenario:
- Set up XML sitemap including node content of type Basic page
- Create a basic page
- Configure cron to run nightly
- Leave the site for a 15 days without changing any pages
- Edit a page
This is a perfectly normal scenario for a site that changes fairly rarely. However there are now errors that stay until the next nightly cron run:
- On admin/config: One or more problems were detected with your Drupal installation. Check the status report for more information.
- On /admin/reports/status: The XML cached files are out of date and need to be regenerated.
False alarms can waste time and should be avoided. It's particularly a problem for people (like me) who are responsible for a fairly large number of sites that all change fairly rarely. In such cases, it makes sense to have mechanisms to gather status reports from all the sites and flag up errors. With many sites, the false alarms can become a nuisance.
In terms of a fix, the simplest thing might be to change xmlsitemap_cron to set xmlsitemap_generated_last if xmlsitemap_regenerate_needed is FALSE. I.e. make the variable to mean "last time we successfully generated whatever needed doing". This seems very simple to code, and I am happy to provide a patch.
Or as an alternative, store a timestamp when xmlsitemap_regenerate_needed was set, and only flag an error based on time elapsed from that time.