Bug Report: Text corruption when using Japanese keyboards on iOS GitHub Mobile

[shuhei1101]

Summary

When using a third-party Japanese keyboard on iOS, the text may temporarily become corrupted under certain conditions, causing the keyboard to stop input.
It seems that the GitHub Mobile code editor internally modifies and restores the text field during this process.

Steps to Reproduce

1. Enable a third-party Japanese keyboard on iOS
2. Open the code editor in the GitHub Mobile app
3. Enter あいうえお
4. Move the cursor
5. Use a small-character conversion key (e.g. to change お into ぉ)

Actual Behavior

• Immediately after conversion, the character え disappears and the text becomes あいうぉ
• The keyboard detects a mismatch and stops input
• A few milliseconds later, the GitHub app restores the text to あいうえぉ
• However, since the keyboard has already aborted input, the user cannot continue typing

Expected Behavior

• After conversion, the text should remain correct as あいうえぉ without corruption

Notes

• This issue does not occur in standard iOS text fields
• It only appears in custom text editors like the one in GitHub Mobile
• Similar problems have been observed in other apps (e.g. Google Sheets) with custom editors

[VictorMoni]

Hi @shuhei1101

Thanks for documenting this issue so clearly! 🙌
The detailed steps and expected behavior make it much easier for the GitHub Mobile team to reproduce.

I’ve also seen similar problems with custom keyboards on iOS, so it looks consistent with what you described.
Hopefully the team can address it in a future update. 🚀