Error in Chrome when trying to convert a specific UTF-8 sequence

[smuehlst]

How to reproduce:

• Open https://r12a.github.io/app-conversion/ in Chrome (I used 71.0.3578.80)
• Paste the following into the "UTF-8 code units" field: f4 8f bf be f4 8f b3 b9
• Click "Convert" button next to the "UTF-8 code units" field

Expected result:

UTF-8 sequence is converted successfully or error message about invalid UTF-8 sequence generated.

Actual result:

The Chrome tab crashes.

When I try the same steps in Microsoft Edge I get U+10FFFEU+10FCF9 as the result.

It is unclear to me whether this is a bug in Chrome or in app-conversion itself.

[frzsombor]

I also found that specific characters causes a Chrome tab crash.
If I paste the 💬 emoji into the first "green" field, chrome crashes if I click "Convert".

However, I also found that if I use the "old version", there is no problem with my example.

Edit: I just noticed that #6 reports a similar problem

[smuehlst]

The original issue is no longer reproducible.