(Case 1033895) Removing CanvasScaler corrupts UI, which cannot be undone

It is possible to corrupt the UI by removing a CanvasScaler Component. The UI corruption is not reversible, Undo does not work.

Reproduce

• Open Assets/Scene.unity
• Move "Canvas 2" into "Canvas 1" in Hierarchy window
• Select "Canvas 2" and remove the "CanvasScaler" Component

=> Observe how this affects the size of the green image, which is part of "Canvas 1".

• Click "Edit > Undo"

=> Observe it undoes the blue image size, but the green image size keeps too big (corrupted).


Expected

1. Removing the CanvasScaler Component of Canvas 2 should not affect elements of Canvas 1?
2. Undo functionality should work always, it should properly undo both, the green and blue image sizes.

 

QA was able to reproduce the issue, good job! It has been added to the public issue tracker now:
https://issuetracker.unity3d.com/is...nvasscaler-corrupts-ui-which-cannot-be-undone

According to the report in the public issue tracker, QA was able to reproduce this issue with various earlier versions than 2018.2.