I guess, it is somehow related to the "Triple Click" feature that is used somewhere in Ko libs. 1) Click fast, click much, click long Firstly, you will get a message that the layer is locked and painting is impossible (although it is not locked of course). Then the tool will be switched to Default Tool automatically.
Yes, pretty easy to reproduce.
Git commit f7e58c09c0167fcf984b369e43ac6c206e8e4b7f by Dmitry Kazakov. Committed on 12/12/2013 at 13:17. Pushed by dkazakov into branch 'master'. Fix too fast mouse clicks (triple clicks) issue M +5 -0 krita/ui/tool/kis_tool.cc M +1 -0 krita/ui/tool/kis_tool.h http://commits.kde.org/calligra/f7e58c09c0167fcf984b369e43ac6c206e8e4b7f
Git commit e2ccd93765584816da70af5747e7ef7b1ce71422 by Dmitry Kazakov. Committed on 12/12/2013 at 13:17. Pushed by dkazakov into branch 'calligra/2.8'. Fix too fast mouse clicks (triple clicks) issue M +5 -0 krita/ui/tool/kis_tool.cc M +1 -0 krita/ui/tool/kis_tool.h http://commits.kde.org/calligra/e2ccd93765584816da70af5747e7ef7b1ce71422
Git commit e0cbb305bd5b48f1ab7e310c05fd7b5caa899755 by Boudewijn Rempt. Committed on 26/06/2017 at 13:57. Pushed by rempt into branch 'rempt/touch-painting'. Remove the triple-click event from KoToolBase This was added in commit a7a75f0056abf59cbce27957ab7fb0b6e64e2cb2 Author: C. Boemann <cbo@boemann.dk> Date: Thu Jan 12 22:13:26 2012 +0100 to make it possible to select text with triple-click. It broke Krita, so was worked around in commit e2ccd93765584816da70af5747e7ef7b1ce71422 Author: Dmitry Kazakov <dimula73@gmail.com> Date: Thu Dec 12 17:17:37 2013 +0400 Fix too fast mouse clicks (triple clicks) issue And we just don't need it at all anymore now that the text tool is deprecated. M +0 -5 libs/flake/KoToolBase.cpp M +0 -8 libs/flake/KoToolBase.h M +4 -42 libs/flake/KoToolProxy.cpp M +1 -6 libs/flake/KoToolProxy_p.h M +0 -5 libs/ui/tool/kis_tool.cc M +0 -1 libs/ui/tool/kis_tool.h M +0 -22 plugins/flake/textshape/TextTool.cpp M +0 -13 plugins/flake/textshape/TextTool.h https://commits.kde.org/krita/e0cbb305bd5b48f1ab7e310c05fd7b5caa899755
Git commit 0a2002ff58ee46933352fb9446141cc37f77346c by Boudewijn Rempt. Committed on 26/06/2017 at 14:56. Pushed by rempt into branch 'rempt/touch-paint-4'. Remove the triple-click event from KoToolBase This was added in commit a7a75f0056abf59cbce27957ab7fb0b6e64e2cb2 Author: C. Boemann <cbo@boemann.dk> Date: Thu Jan 12 22:13:26 2012 +0100 to make it possible to select text with triple-click. It broke Krita, so was worked around in commit e2ccd93765584816da70af5747e7ef7b1ce71422 Author: Dmitry Kazakov <dimula73@gmail.com> Date: Thu Dec 12 17:17:37 2013 +0400 Fix too fast mouse clicks (triple clicks) issue And we just don't need it at all anymore now that the text tool is deprecated. M +0 -5 libs/flake/KoToolBase.cpp M +0 -8 libs/flake/KoToolBase.h M +5 -41 libs/flake/KoToolProxy.cpp M +1 -6 libs/flake/KoToolProxy_p.h M +0 -5 libs/ui/tool/kis_tool.cc M +0 -1 libs/ui/tool/kis_tool.h M +0 -22 plugins/flake/textshape/TextTool.cpp M +0 -11 plugins/flake/textshape/TextTool.h https://commits.kde.org/krita/0a2002ff58ee46933352fb9446141cc37f77346c