Incorrect handling of deleted thread root messages

[janogarcia]

Steps to reproduce

1. Make sure you have Settings > Preferences > Timeline > Show a placeholder for removed messages disabled.
2. Create a thread.
3. Delete the root message.

Note: We decided long ago to keep thread root messages always visible, even if the Show a placeholder for removed messages is disabled.

Outcome

It seems a regression has been introduced for deleted root messages, breaking the previous correct behavior.

Now, deleting a root message will:

• 🔴 Make the root message and thread summary disappear completely from the main timeline.
• 🔴 Keep showing the original contents for the deleted message in the thread timeline.
• ✅ Show the correct "Message deleted" status in the thread list.

What should happen instead:

Please refer to the Figma mockups for the detailed context/flows.

In short:

• Show the "Message deleted" state for the root message and keep displaying its thread summary in the main timeline (instead of "Make the root message and thread summary disappear completely from the main timeline.")
• Immediately stop showing the original content for the deleted message in the thread timeline (instead of Keep showing the original contents for the deleted message in the thread timeline.)-

URL for webapp

develop.element.io

Application version

Element version: 071a541-react-4e4ce65f584b-js-a3f5ec1ba2fa Olm version: 3.2.8

Will you send logs?

Yes

[t3chguy]

🔴 Make the root message and thread summary disappear completely from the main timeline.

So I think the issue is a bit more nuanced, the thread is still there, attached to the Message deleted, its just that its collapsed into the Summary. @janogarcia what should we do here?

[janogarcia]

@t3chguy Unsure if I've understood your remarks.

I've edited the issue description to hopefully add more context. Please find all the details about the expected behavior in the Figma mockups for the Deleting the root message Flow.

It had been working correctly for months I'd say, only recently stopped working (last week) .

Maybe @gsouquet can clarify / shed some light on your question?

[janogarcia]

@t3chguy Another odd behavior that was introduced las week on deleted messages:

As stated in the issue description, the root message contents are not immediately hidden from the thread timeline. It keeps showing the original message.

When reloading the page the deleted root message will be rendered as expected in the thread timeline ("Deleted message" state) but preceded by a "You can't see earlier messages" notice which shouldn't be there.

[t3chguy]

"You can't see earlier messages" notice which shouldn't be there.

this happening randomly is unrelated to threads - #21434

[janogarcia]

@t3chguy I was not aware of #21434, thanks. It happens consistently for the case I described, though, if that helps track it down.

[janogarcia]

@t3chguy Updated the issue description after further internal discussion. I added a note on the decision we made long ago about displaying deleted root messages even when the Settings > Preferences > Timeline > Show a placeholder for removed messages option is disabled.

[t3chguy]

Cannot reproduce even with that option disabled.

[janogarcia]

On my end, the deleted root messages consistently disappear from the main timeline as soon as I disable said option.

Element version: e638abf-react-9b2944294cf0-js-d0b964837f28
Olm version: 3.2.8

[t3chguy]

I tested on the same version, with & without show hidden events enabled, the root message never vanished from my room timeline.