PC3 ToolButtons do not have the same size as PC2 and QWidgets ToolButtons. This patch
Now PC3 ToolButtons have the same size as PC2 and QWidgets ones by default if you don't
override the icon.height and icon.width properties.
Now will always be > 0, right?
Good catch; only set icon height and width if an icon has actually been provided
On second thought, maybe it was fine. Layout.preferredWidth should not have any effect when icon is not visible anyway. And negative value could be set if needed.
It could be my broken build. But this is what I see with X11 and scale 1.75.
Looks like @mart just did this in D27396.