Automatically detect and resolve when a file is moved on Wikimedia Commons

[MichaelNMaggs]

A juror has reported that when he clicked the Full Size link, the new page it opened was a 404. The preview was OK. Digging around, he found that the image had been renamed on Commons, and that Montage was not following the redirect.

Btw, does Montage degrade gracefully in the event that the Commons image has been deleted?

[slaporte]

Montage adds files as entries when the round is created, but doesn't (currently) update the entries when files are moved or deleted in Commons.

I think it should work like this:

• The client validates if an entry loads correctly from Commons.
• If the file doesn't load, it calls an "update" endpoint on the backend that detects if it has been deleted or moved.
  • If the file has been moved, the entry can be updated in Montage.
  • If the file has been deleted, the entry is disqualified from further voting and flagged for the campaign coordinators to investigate further.
  • (Coordinators can requalify the entry if something has gone wrong, or import a selected new file if necessary)

[MichaelNMaggs]

Looks good. Where the file has simply been moved (as opposed to deleted) I think the Montage entry should be updated automatically and transparently. The fact that a file has moved shouldn't be an issue that jurors have to worry about at all; it should 'just work'

[slaporte]

Montage should also do a similar check for moved files on import. For example, an old list of filenames may have a few redirects after a while.

[atsirlin]

Currently, file import fails when the list contains at least one file that has been moved. A quick fix would be to skip those files instead of ruining the whole file import. For a proper fix, the import procedure should follow the redirect and import the file from its new location.

[MichaelNMaggs]

It wouldn’t be acceptable to skip moved files, at least without providing a notification, as that would amount to an image being effectively barred for no reason.