MIME type offered for webp downloads is possibly incorrect?

[lbeltrame]

Posting here as I'm not sure if it's an issue in SD.Next or upstream Gradio.

I've noticed that if you set webp as image format, the MIME type of the download is wrongly set as text/plain instead of image/webp:

curl -s -I "http://127.0.0.1:7860/file=/tmp/gradio/2aa08251e8db3cbf16cd04f036175e65ac4c0952/00084-256793276-animagine-xl-3.0-1girl%20solo%20standing%20leaning%20forward%20arms%20behind%20back.webp" | grep -i "^Content-Type:"
content-type: text/plain; charset=utf-8

But at least looking at the file's magic number identifies it as webp:

file 00084-256793276-animagine-xl-3.0-1girl\ solo\ standing\ leaning\ forward\ arms\ behind\ back.webp 
00084-256793276-animagine-xl-3.0-1girl solo standing leaning forward arms behind back.webp: RIFF (little-endian) data, Web/P image

This is problematic for example if you want to download images from mobile, as they will be interpreted as text. However I'm not sure if this is a problem with Gradio (a quick glance at their issue tracker did not show anything) or in SD.Next itself.

[vladmandic]

it is a gradio thing, but i can still provide additional mime types from sdnext - its fixed in dev.