Created attachment 109899 [details] Example image Painting beyond the top or left borders of the canvas appears to produce a dashed version of what was drawn, with a 128px spacing. This seems to have broken at or around the time that multithreaded brushes were added. In the attached image, I drew lines that started on the canvas and ended outside of it, then moved the layer down and to the right.
Created attachment 109905 [details] (Video example) Yes, I can reproduce this bug on Ubuntu 14.04 with Krita 4.0.0-beta1.1 (OpenGL was enabled) (see video)
One for Dmitry then. It is a regression, but I would not classify it as a release blocker.
Confirm, I can reproduce. It seem to be related to the new multithreaded pixel brush and the fact that the painting rectangles have negative offset
Git commit 18b549c1ee549b4be6182e368a42750adf56cce8 by Dmitry Kazakov. Committed on 06/02/2018 at 16:48. Pushed by dkazakov into branch 'master'. Fix division in KisAlgebra2D::splitRectIntoPatches() Here we should round the division result towards negative infinity instead of zero point. M +19 -0 libs/global/kis_algebra_2d.h M +1 -1 libs/image/brushengine/kis_paintop_utils.cpp M +1 -1 libs/image/kis_painter.cc M +7 -4 libs/image/krita_utils.cpp M +23 -0 libs/image/tests/kis_algebra_2d_test.cpp M +2 -0 libs/image/tests/kis_algebra_2d_test.h https://commits.kde.org/krita/18b549c1ee549b4be6182e368a42750adf56cce8