Looks like copied tempfile need to be flushed before further processing. This issue won't happen if the uploaded file has enough file size.
1.2 KiB
32x32px
1.2 KiB
32x32px
![](/vbatts/mastodon/raw/commit/0b683ee644c070aa9d8a4577b8bc0545c2fef777/spec/fixtures/files/mini-static.gif)