There is no inline documentation or note in the README in the PageImages extension about how PageImages are populated and what developers should be wary of when working with this codebase. Let's add some to protect against incidents such as https://wikitech.wikimedia.org/wiki/Incident_documentation/20161202-20161201-PageImages
|mediawiki/extensions/PageImages : master||Document page property names|
|Resolved||ovasileva||T146758 Inform community on changes to images API|
|Resolved||None||T152239 [2hrs] PageImages code should have documentation warning developers about caching implications|
It seemed an inline comment was most appropriate here.
We should document the config variables in a readme and how they behave but I don't see how this would help protect us against license issues like that in the incident since there is no config switch that impacts it.
This task is about documenting caching
implications gotchas around the licensing-related config variables and not necessarily licensing issues themselves. A note in the README seems appropriate.
I couldn't find an announcement, though this is likely not finding the right Google incantation. The most recent changes have been discussed a number of times on reading-wmf and well documented on mediawiki.org.
I think this task can be considered done since the new behaviour is the default and it's not flagged.