Fix execution of "windowbuttonmotionfcn" with uipanels (bug #46151) * Canvas.cc (Canvas::canvasMouseMoveEvent): decide here to update the currentpoint and run "windowbuttonmotionfcn" if the latter is not empty * Canvas.h: remove unused "enableCurrentPointUpdates" method and "m_updateCurrentPoint" attribute * Figure.h: declare a new private method "enableMouseTracking" * Figure.cc (Figure::Figure): use "enableMouseTracking" instead of "update" on "windowbuttonmotionfcn". * Figure.cc (Figure::update): mouse tracking is now enabled unconditionally so remove unused case "windowbuttonmotionfcn". *Figure.cc(Figure::eventNotifyAfter): enable mouse tracking on new children widgets.

header = '{date|shortdate}  {author|person}  <{author|email}>\n\n'
changeset = '\t{desc|tabindent|strip}\n\n\tFiles: {files|stringify|fill68|tabindent|strip}\n\n'