Steps

1. Connect to core
2. In … → Client Settings, under Autocomplete, ensure Double tap to autocomplete is enabled (the default)
3. Open an IRC channel and load backlog until normal chat messages are visible
   • E.g. #quasseldroid
4. Focus the chat input box
5. Double tap a message from any user
   • E.g. Not-#### the notification bot, or justJanne
6. Observe the chat input box
7. Go to the home screen via the Home button/gesture
   • Do not use the Back button/gesture as that will destroy the activity
8. Open Quasseldroid
9. Observe the chat input box
10. Optional: keep going to the home screen and returning to Quasseldroid, or switch apps, or lock the screen/unlock
11. Optional: to workaround the issue, switch to another buffer and back, or use the Back button/gesture to finish the activity

Expected

Only one instance of nickname: is visible, e.g. justJanne: .

Actual

Every time Quasseldroid regains focus, another instance of nickname is appended, e.g. justJanne: justJanne justJanne.

Details

Tested using Android 10 with Gboard on a Pixel 4 XL.