Qtox: Fedora Plasma close to tray restores to blank window

[anthonybilinski]

Brief Description

OS: Fedora 30 with KDE Plasma
qTox version: v1.16.3+
Commit hash: 48d23234b7b34b1a8c750b75f6510f5b30def4be
toxcore: 0.2.10
Qt: 5.12.5
Hardware: Desktop

Reproducible: Always

Steps to reproduce

1. Enable "Close to tray" in settings.
2. Close qTox
3. Run a second instance of qTox, or click "show" on the tray icon's menu

Observed Behavior

The qTox window opens, but the entire windows is blank:

Expected Behavior

The window restores correctly.

Additional Info

"Minimize to tray" functionality works correctly. This issue isn't reproducible on Ubuntu 19.04 with gnome.

Credit to @TheDcoder for first identifying the issue in https://github.com/qTox/qTox/issues/5846#issuecomment-544233302.

[TheDcoder]

I just want to note that this issue doesn't seem to be effecting the AppImage, I have been using the latest stable AppImage since a few weeks and I never observed this issue.

(Same OS - Fedora 30 with KDE)

[Hasshu]

Fedora 30 KDE with the AppImage (v1.16.3) here; no such problem either.

qBittorrent had a similar issue recently (fixed in qbittorrent/qBittorrent#10590), and it seems to be related to the QCloseEvent class. The AppImage probably works because it comes with an older version of Qt.

[cerebrum]

The same problem exists in Gentoo with net-im/qtox-1.16.3, dev-qt/qtgui-5.12.5 and kde-plasma/plasma-desktop-5.16.5.