ZWJ emoji as account symbol only shows the first element of the emoji

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

Thunderbird for Android

App version

11.0

Where did you get the app from?

F-Droid

Android version

GrapheneOS 16 Build 2025081400

Device model

Pixel 9a

Steps to reproduce

1. Go to Settings
2. Edit one account
3. General Settings
4. Account name
5. Put any ZWJ Emoji as the first character, e.g. 🐦‍🔥 (Phoenix)

Expected behavior

In the account overview the account symbol is the phoenix

Actual behavior

The account symbol is 🐦 (Bird, the first symbol of the ZWJ sequence)

In the settings the emoji is correctly displayed as phoenix.

Logs

The Phoenix emoji is a ZWJ sequence combining 🐦 Bird, Zero Width Joiner and 🔥 Fire. These display as a single emoji on supported platforms.

https://emojipedia.org/phoenix-bird

Note there can also be longer sequences like Family with two kids 👨‍👩‍👧‍👦

_

Let me say thank you for introducing the possibility to customise the account symbol with two letters or a single emoji.

Seems like the one emoji instead of two characters was even implemented purposefully instead of two emojis.

Reproduce the issue by setting a ZWJ emoji such as 🐦‍🔥 as the first account-name character, then compare the account overview with the settings display. Trace the account-symbol rendering entry point and verify that the complete ZWJ sequence, including longer sequences such as 👨‍👩‍👧‍👦, appears as one symbol in the account overview.