Thanks for looking into that Marco! I think the problem might be indeed something with indicator-appmenu. I checked appmenu-qt5 and everything seems fine there: appmenu-qt5 fetches the related QMenu and exports it through DBus. During the hide/show the menu stays the same, the window stays the same, so appmenu-qt5 has no reason to re-export it again as all the previous contents are valid - and appmenu-qt5 really doesn't do much more. It only re-exports menus when the menu parent changes, or the menu itself. Here it has no reason to do that as none of the important bits (the winId or the QMenu) changed. But somehow, the once exported menu is invalidated/lost somewhere.
Adding indicator-appmenu to the investigation. ** Also affects: indicator-appmenu (Ubuntu) Importance: Undecided Status: New ** Changed in: indicator-appmenu (Ubuntu) Assignee: (unassigned) => Łukasz Zemczak (sil2100) ** Changed in: indicator-appmenu (Ubuntu) Status: New => In Progress -- You received this bug notification because you are a member of DX Packages, which is subscribed to appmenu-qt5 in Ubuntu. Matching subscriptions: dx-packages https://bugs.launchpad.net/bugs/1451946 Title: Menu disappears if a window is hidden and then shown again Status in appmenu-qt5 package in Ubuntu: In Progress Status in indicator-appmenu package in Ubuntu: In Progress Bug description: If a Qt 5 application window becomes hidden (QWidget::hide()) and then shown again, it loses its global menu. I have attached a simple application to show the problem. It occurs on Ubuntu 14.04 LTS with stock Qt 5.2.1. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/appmenu-qt5/+bug/1451946/+subscriptions -- Mailing list: https://launchpad.net/~dx-packages Post to : dx-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~dx-packages More help : https://help.launchpad.net/ListHelp