If you try to draw on a clone layer the brush outline "sticks" to where you clicked. Not sure how this should behave but this doesn't feel comfortable. If a clone layer should not be drawable on, which makes sense, perhaps there should be some kind of tool black/whitelisting.
Git commit eca9a7633e1e0ff3b553328fe79bb13aa62432eb by Boudewijn Rempt. Committed on 30/01/2018 at 08:24. Pushed by rempt into branch 'master'. Show a warning when trying to paint on a clone layer This shows the same warning as when trying to paint with the freehand tool on a vector layer. Rectangle etc. tools also should show the warning, but don't yet. Note that this isn't a complete solution, but generalizing the message would need changes to the strings, and we're in string freeze now. Another option would be to enable/disable tools dependent on the type of layer selected, but that is a big refactoring, since tools only react to the type of shape selected at the moment. M +2 -1 libs/ui/tool/kis_tool_freehand.cc M +3 -0 libs/ui/tool/kis_tool_paint.cc M +2 -1 libs/ui/tool/kis_tool_paint.h https://commits.kde.org/krita/eca9a7633e1e0ff3b553328fe79bb13aa62432eb
We might be able to close this one. I think showing the message like it does now is probably better than disabling in this case. Usually when things like this are disabled, it creates a user support requests with things like "Krita won't let me paint". I think the message helps educate people "why" the tool won't work.
I also recently extended this to other tools that cannot work on clone layers.