Broken text wrapping in grid column

  <Grid ColumnDefinitions="*, *">
    <TextBlock Grid.Column="1"
               VerticalAlignment="Center"
               Text="He determined to drop his litigation with the monastry, and relinguish his claims to the wood-cuting and fishery rihgts at once. He was the more ready to do this becuase the rights had becom much less valuable, and he had indeed the vaguest idea where the wood and river in quedtion were."
               TextWrapping="Wrap"/>
  </Grid>

[grokys]

This appears to be caused by Grid caching the measurement of the child control, and applying that cache to subsequent measurements of a different size:

https://github.com/AvaloniaUI/Avalonia/blob/65234e8e43cdbff29791caecf224cbb4b05062be/src/Avalonia.Controls/Grid.cs#L317

[Gillibald]

My window has a size of (1920,1080) and the Grid tells the TextBox it has available space of (960,16) but the text layout has a height of 32 so one line is cut off. Somehow when you use VerticalAlignment=“Center” the FormattedText doesn’t get enough space. When VerticalAlignment=“Stretch” is used everything works fine.

Update:

Okay, it seems that this cache has an old value. https://github.com/AvaloniaUI/Avalonia/blob/master/src/Avalonia.Controls/Grid.cs#L315

When I debugged this I realized that the FormattedText is constructed twice. The first time the available space is infinity and the second time and old value of the cache.

Removing the caching fixes the issue. Every time a window is resized or shown the layout is calculated twice. The first time the grid passes the whole available space without column calculations and the second time with column calculations but with outdated cached desired size. The second layout pass should only be cached not the first one.