Reverted my fix for bug #5539, brush circle cursor is slow. The fix was causing more sculptmode drawing artifacts for some users. Since this is a non-critical performance related bug, it can wait until after 2.43.

source/blender/src/space.c

@@ -1074,7 +1074,7 @@ static void winqreadview3dspace(ScrArea *sa, void *spacedata, BWinEvent *evt)
 				}
 				else if(event!=LEFTMOUSE && event!=MIDDLEMOUSE && (event==MOUSEY || event==MOUSEX)) {
 					if(!bwin_qtest(sa->win))
-						sculpt_paint_brush(0);
+						allqueue(REDRAWVIEW3D, 0);
 				}
 			}