Fix endless loading timeline if opened at non-existing event

[SpiritCroc]

Signed-off-by: Tobias Büttner dev@spiritcroc.de

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

Pass M_NOT_FOUND and M_FORBIDDEN server errors to timeline listeners.

Motivation and context

When opening a permalink for a non-existing event (e.g. the event has been deleted on the server), or a forbidden event (e.g. after a moderator redacted the event), we want to tell the user the event wasn't found, and instead reload the timeline without initial eventId. Before, it was just loading endlessly without any indication of a reason.

Tests

Create a permalink for a room with changing the eventId to something like "$doesntexist", and click it.

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[bmarty]

Thanks for the PR. This LGTM!

[ganfra]

Nice catch, thanks, forgot to rebranch this during the rework...