https://commons.wikimedia.org/w/index.php?title=File:Bangkok_street_food_-_Thanee_Khao_Moo_Daeng_(51362795506).jpg&diff=719608451&oldid=708983056

this edit corrected an anomalous category

[[Category:[[Category:Kitchen scales]]]]

i assumed this redundant wikitext was added when i copypasted "Category:Kitchen scales" in uploadwizard. at the time of my upload, the target category already exists, so it's unlike the error when the cat does not yet exist ( [[Category:Category:Example]] ).

Steps to replicate the issue

• https://commons.wikimedia.org/wiki/Special:UploadWizard
• copypaste "Category:Example" when adding categories
• somehow, i'm not sure how exactly, resultant wikitext will have one redundant layer.