How to reproduce:
-right-click channel label (or flag label), context menu with Delete command is displayed
-move mouse to another label and right-click again, so context menu is closed
-don't move mouse cursor and right-click again
-context menu is not displayed
Reason: mouse_point_ is used in contextMenuEvent() handlers instead of event->pos(). In described situation mouse_point_ contains (-1, -1) from ViewWidget::leaveEvent(QEvent*).
Patch is attached.
Created attachment 174 [details]
Use event coordinates instead of cached mouse_point_