Splitting off from T32551.
Occasionally an upload succeeds without a description page being created.
Its unclear what circumstances this happens. Possibly an error connecting to externalstorage causes an exception to be thrown, or something of that nature.
There is a list at https://commons.wikimedia.org/wiki/User:Ilmari_Karonen/Queries/Zombie_images
As of this writing, some examples: File:Jersey, Corbiere Lighthouse by moonlight, Channel Islands-LCCN2002696513.tif, File:Palais de Justice and bridge to exchange, Paris, France-LCCN2001698506.jpg
File:Château du Martinet - façade nord.JPG is missing log entries, but the page is fine.
Most of the examples seem to be from mass upload tools (GWToolset and flickr2commons). I expect that to just be coincidence though
Consider bug T32551 to be about the referential integrity issues where people couldn't create the pages due to missing revisions, and this to be about the larger issue where sometimes pages aren't created