Last modified: 2012-07-17 00:06:20 UTC
calling ?action=purge on a file page, all video derivatives are removed from the disk, the page still lists them since the transcode table is not purged. video transcodes should not be deleted if the page is purged.
we had a flag to protect the files from being removed i.e bug 27641 .. but I guess that patch got re-factored or deprecated in the mean time some how?
looks like MediaHandler subclasses can implement filterThumbnailPurgeList now, pushed a patch to https://gerrit.wikimedia.org/r/6472 to not delete any derivatives.