Calling QTrayIcon hide() with an immediately following show() causes the context menu to malfunction

Calling hide() and immediately show() directly after causes the 'MenuBar' object of the dbus StatusItemNotifier service of the application in question to disappear and as a result the context menu which is described under that object will not show up.

The program attached should not show a context menu but trigger a log message (may vary):

Call to AboutToShow() failed: "No such object path '/MenuBar'"

Inspecting the test program's statusnotifieritem will show MenuBar is missing.

I noticed this when I tried to open the context menu of Seafile (which switched to Qt5 lately) and it was not quite clear what was causing this problem at first. I am aware that SNI is integrated in Qt5 and for Qt4 an extra module 'sni-qt' is necessary. In seafile, using hide and show together seemed to be meant as a fix on Ubuntu where the (Seafile) tray icon just disappeared.