Shading Tool breaks Undo functionality

[Alex Miranda]

Pixelorama version:
v0.11.2-stable

OS/device including version:
KDE Neon 5.27 (Linux)

Issue description:
After using the Shading tool and changing to another tool, Undo/Redo does not work properly.

Steps to reproduce:

1. Select the Shading tool
2. Paint on the canvas
3. Select any other tool
4. Try to Undo. An "Undo: Draw" message appears, but the canvas does not get reverted.

[Variable]

Thanks for reporting. This bug will be fixed in the next version (0.11.3)
In the meantime you can use the version below (these doesn't have the bug)
Windows-64bit.zip
Linux-64bit.zip

[Emmanouil Papadeas]

Fixed by 331c46c (and #916 for 0.x)