TextBlock text wrapping: Sometimes duplicates and leaves characters behind on wrap

Development Setup

• Avalonia v0.9.999-cibuild0006280-beta (latest as of 2020-03-10 at 1:50 PM EDT)
• .NET Core 3.1
• Visual Studio 16.4.5
• Windows 10
• Repo: https://github.com/Deadpikle/AvaloniaBugs/tree/master/ItalicTextWrapping

Bug description

Sometimes, when wrapping, certain characters are left behind on text wrapping and show up in two places. This only seems to happen with the NotoSans-Italic font (in repro project below); with normal font or default Windows font w/Italic FontStyle, things wrap properly.

This is easiest shown by a picture:

Notice how “applies” gets broken up on text wrapping – the “a” is left on the first line and appears again on the second line with the rest of the word.

I’m not sure if the --auth line breaking is working right either? I’d prefer that to show up on one line, since there’s room, but that’s debatable. Edit: As Gillibald mentioned, this is working properly, and the non-breaking hyphen (\u2011) works great in my app.

XAML:

<TextBlock Text="Whether to turn off HTTPS. This option only applies if Individual, IndividualB2C, SingleOrg, or MultiOrg aren't used for --auth."
             Margin="0,4,0,0"
             Width="238"
             FontFamily="avares://ItalicTextWrapping/Assets/NotoSans-Italic.ttf#Noto Sans"
             TextWrapping="Wrap"/>

Repo for easy reproducing: https://github.com/Deadpikle/AvaloniaBugs/tree/master/ItalicTextWrapping

Thanks!

[Gillibald]

#4240 I think I finally fixed this. Still have to verify 😅

[Gillibald]

This issue is super weird. Somehow Skia renders an extra character with this particular font.