Thread summary is not displayed for root messages in search results

[frakic]

Steps to reproduce

1. Where are you starting? What can you see?
   -I'm in a public room with some threads
2. What do you click?
   -I click the Search icon and type in the content of some root message
3. More steps…
   -The message is found but underneath, instead of showing the thread summary, it just says "From a thread"

Outcome

What did you expect?

To see the thread summary underneath the root message in search results

What happened instead?

It just says "From a thread"

Operating system

Windows 10 Home 21H1

Browser information

Firefox 98.0.1 (64-bit)

URL for webapp

https://develop.element.io

Application version

Element version: 071a541-react-176e49e31259-js-905a884f72e8 Olm version: 3.2.8

Homeserver

matrix.org

Will you send logs?

No

[t3chguy]

Requires spec matrix-org/matrix-spec-proposals#3666 & Synapse support

[t3chguy]

The message is found but underneath, instead of showing the thread summary, it just says "From a thread"

This is no longer the case, we will show the thread summary if we know it locally already, else nothing (because we don't know that its a thread root)