When a QLabel is set on QStatusBar, the internal connection list is not cleared after clearing the text of the label. The list just grows each time the text is set on the label:-

> I think I discovered what happens after setting the string:
> After changes of the QStatusBar widgets the main window layout is
> recalculated and this will also recalculate the tool bar layout.
> Here the method
> void QToolBarLayout::setUsePopupMenu(bool set)
> is called with parameter set=false.
> This calls
> QObject::connect(extension, SIGNAL(clicked(bool)),
> this, SLOT(setExpanded(bool)));
> Hence, a new connection is added to the tool bar extension object with
> every layout change.
> The size of the connection list for the signal "clicked(bool)"
> (QObjectPrivate::connectionLists[29]) grows more and more and correlates
> with the number of QLabel::setText calls.