I was not yet able to reproduce but a BMP file (which is not allowed on Commons) ended up on the server twice:
- Uploaded with Android App; https://commons.wikimedia.org/wiki/Special:Undelete/File:Deamado_ko.png.bmp
- Chunked upload; https://commons.wikimedia.org/w/index.php?title=Special:Log&page=File%3ATest-file.bmp
Version: wmf-deployment
Severity: normal