is-layout-flow gets applied contextually in site editor, causing layout shift

[jasmussen]

In the site editor, using a layout involving 3 columns of latest posts, when you click between these three columns, the layout shifts:

This appears to be caused by a margin that is added to inner items between deselected and selected. When inspecting. it becomes clear that a selected column has a is-layout-flow CSS class applied to the column li item:

The class is-layout-flow applies some margin to place the inner contents:

If this margin is appropriate for the column, it should be applied to all columns, not just the selected one. So far I've been able to reproduce it using only the Columns block, and it may be limited to just that block.

[jasmussen]

@tellthemachines can you reproduce this? I recall you working on flow layout before, any input you have would be great, thank you.

[tellthemachines]

Hmm I can't reproduce that on trunk. The is-layout-flow classname is applied on the ul, but not on any of its li whether they are selected or not. The li aren't blocks in themselves, so they shouldn't ever have that class unless it's being applied independently of the layout support.

Could you share some more info on your environment, theme, plugins etc. that might help isolate the cause?

[jasmussen]

Thank you for looking. Indeed retracing my steps now, I'm unable to reproduce. The is-layout-flow is no longer applied to the individual post columns. Closing as fixed!