Audio player displays `body` as title even when `filename` is present

[twassman]

Steps to reproduce

1. Send an audio message (m.audio) containing both body and filename (differing from each other).
2. View the message.

Outcome

What did you expect?

The filename is the filename, and so should be displayed as the title of the audio file (in the player area), while the body is the caption, and so should be displayed as a inline message (see spec as of v1.16).

What happened instead?

The body was displayed in both locations:

(Interestingly, this does seem to display correctly when the audio message is quoted. It also displays correctly for m.file and m.image, but not for m.video — see #31117.)

Operating system

No response

Browser information

No response

URL for webapp

staging.element.io

Application version

Element version: 1.12.3-rc.0

Homeserver

No response

Will you send logs?

No