MediaWiki.org has just been a victim of the
'Commons deletion issue'. An
image from the Crystal icon set that was prominently used in many
navigational pages, including the main page, was deleted from Commons and
suddenly
MediaWiki.org is full of broken images. The deletion was valid (it
was a duplicate file) but the fact that the actions on SiteA can affect
SiteB so radically is really rather worrying...
A technical solution would be for people deleting files on commons (for this
kind of reason) to replace the page with a redirect page, and for these
redirects to be resolved by MediaWiki when linking to a shared file. This
won't solve all problems of course, but it would help for this kind of
situation (or e.g. a GIF being replaced by an SVG). Of course, I'm sure
there are many ways this could be abused as well...
I don't know if anyone has any suggestions to deal with this kind of
problem, or even if it has already been recognised as an issue. The
non-technical answer is, of course, to copy the commons images to the local
wiki, but that kind of defeats the point of commons, doesn't it?
You could just make the image page into a redirect and leave the duplicate
file in place. It's not like deleting files saves disk space, it just
moves them into a private directory.
-- Tim Starling