Detect format of generic file attachment and list under respective Apps & Media tab

[ian]

I can upload an SVG as a generic “file”. It renders in the timeline.

However, the file will not appear under the Apps & Media tab, instead being listed under the “Files” tab, lacking a preview thumbnail.

We should detect or map the type of a generic “file” attachment and then list it under one of Apps, Images, Video or Audio if it is of supported format.

Related:

Extend upload filter with all rendered image formats

I can not upload an SVG file with the image attachment action, because its filter does not match that file extension. The image filter is missing file extensions for many other file formats otherwise whitelisted in the DC rendering code. I can attach it as a file, and after sending it, it renders correctly in the timeline. Amazingly, even SMIL animation works. Related: