BUG: Fixed editor behaviour in restoring correct label.
Created by: mehrtash
To reproduce the issue:
- Load a volume, go to editor and create a merge labelmap.
- With Paint effect paint something with label 1.
- While on Label 1 select eraser, erase something and go back to painteffect.
- Select another label e.g 2.
- Paint something with painteffect. It works fine (paint with label 2).
- Choose another effect (e.g draw or want effect) and it would go back to the label 1 as it only stores the backup label when eraser is selected.
Fix: Backup label should also be set when a new color (not zero) is chosen not only after switching to eraser.