Created attachment 115393 [details] video of square behaviour with HSV slider SUMMARY A "random" square appears rarely when using various sliders. This has happened for many versions (>= 4), but is hard to reproduce. STEPS TO REPRODUCE Reproducible: Rarely Unknown exact steps prior, however it has always been when using sliders, mostly HSV, (ctrl+u), and when the adjustment is cancelled. For a single document it is reproducible until either the document or Krita is closed. It is destructive to the layer, not visual only. OBSERVED RESULT Square created on adjusted layer, destroying content. EXPECTED RESULT No square created. SOFTWARE VERSIONS Qt Version: 5.11.2-1 nvidia: 340xx i3wm on xorg: 4.15 compton: 2.0 ADDITIONAL INFORMATION From observation/memory, this has happened only under i3wm/compton. It may be unrelated to Krita in that case? It happens most often when HSV sliders are adjusted on a bottom single colored layer. That could just be because it is what is used most and because the most pixels are changed when an entire layer that is filled is changed, thus many updates happening at once. If the adjustment is cancelled the square is of the color that was last shown in the instant preview. The square size seems consistent based on past instances. If drawn over the square, it cannot be undone. The square reappears when using slider or adjusting colors. Sorry this isn't much to go on, just thought it should be reported finally as an instance of the issue has been recorded. No other information on this issue was able to be found, which lead to the belief of it being related to something specific in compositing or user configuration. Hope the video explains what is going on better than text. Will record full screen if reproducible when not working on a private project.
"From observation/memory, this has happened only under i3wm/compton. It may be unrelated to Krita in that case?" On the face of it, that would seem unlikely. If you save and load the document, is the square still there?
(In reply to Boudewijn Rempt from comment #1) > "From observation/memory, this has happened only under i3wm/compton. It may > be unrelated to Krita in that case?" > > On the face of it, that would seem unlikely. If you save and load the > document, is the square still there? Happened again and can confirm. There were actually 2 this time, and one fixed itself. Square remains even after closing and loading, and also closing Krita. It's part of the file. However, it doesn't have the same behavior as the first video, it is just part of the layer now once opening. Will do more testing and a video later.
Created attachment 115433 [details] live moment of occurrence Here is an example from 2 months ago, it happened right when pressing 'ctrl+u', didn't notice until after. HSV slider window is hidden due to it only capturing Krita window.
Created attachment 115434 [details] 2 squares Here is the example from today with 2 squares. Didn't capture the moment it happened. One of them fixed itself after painting over an erased section with the background color. It does not seem related to a square brush as like in the previous clip, as this one was without.
Hm, I'm not able to reproduce this, I'm afraid. I still doubt it has anything to do with 3wm, but who knows... I wonder whether this does also happen if you turn off canvas acceleration.
Since switching off of i3/compton (a month or so) this has not happened. (using KDE/GNOME) There are many possible factors, and I have not been able to close in anything. There is clearly some kind of a bug with the visuals, hardware related or not. I thought it could be user error, or because of a square brush, but that still doesn't explain the behavior shown in videos. I've tried setting up macros to repeat steps, recording key presses, to no avail. I won't bore with other details. It could still happen again, but I wanted to document it. It's currently so rare that I'm unable to diagnose further. Closing.
Thanks for getting back to us!