Widget decoration causes node duplication when typing dead-letters

[tommoor]

Bug

I have a widget decoration that is only rendered next to empty paragraphs, when a character is typed the decoration is removed. (For context, It acts as a button to insert content into empty lines).

When typing a diacritic using a dead-letter it results in duplication of the line below. Something about the DOM diffing is not accounting for this case perhaps?

Reproduction

• Open remix: https://elegant-periwinkle-thursday.glitch.me/
• Insert a new line at the top and see the widget appear
• Type a dead letter as the first character in the empty paragraph (On macOS you can use Option+I)
• The line below duplicates

A video of the above behavior, note that typing the dead-letter in a position other than the first character in the paragraph does not reproduce:

Kapture.2022-06-25.at.11.44.36.mp4

[marijnh]

Which browser does this happen in?

[tommoor]

Hey @marijnh – so far I know this has been reproduced in both latest Chrome on macOS (by me), and Firefox on Linux (by original reporter in our application).

[marijnh]

Oh, right, I can reproduce it now. Continued typing before, and didn't notice, due to the layout shifting, that the duplicated paragraph immediately vanished again.