Currently when you try to add filter layer/mask it stays inside layer stack without any name after clicking "cancel". Maybe it could be automatically removed if cancel is pressed...
Yes, this is definitely a bug.
This broke with commit 2a1329ec20a3f16a9c2d29bf057da76786cd0e50 ("Add an option to draw ruler tips as a power of 2"). Pressing cancel when adding a filter mask causes an undo to occur, which, in this case, undoes "Edit guides" instead (see bug 387997).
Git commit f91fa3c18a0cc8d72f3dab8285fc32993c6f6b7d by Thorsten Zachmann. Committed on 04/01/2018 at 05:32. Pushed by zachmann into branch 'master'. Fix command generated when document is created Don't create a command when the unit of the document is changed. Related: bug 387997 M +1 -1 libs/ui/canvas/kis_guides_manager.cpp https://commits.kde.org/krita/f91fa3c18a0cc8d72f3dab8285fc32993c6f6b7d
Git commit 008d4977309776b496a7f38b0764a97bfddc5a8a by Thorsten Zachmann. Committed on 04/01/2018 at 05:33. Pushed by zachmann into branch 'krita/3.3'. Fix command generated when document is created Don't create a command when the unit of the document is changed. Related: bug 387997 (cherry picked from commit f91fa3c18a0cc8d72f3dab8285fc32993c6f6b7d) M +1 -1 libs/ui/canvas/kis_guides_manager.cpp https://commits.kde.org/krita/008d4977309776b496a7f38b0764a97bfddc5a8a