Workaround for a Qt crash on reloading menus #17
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Such random crashes are triggered by Qt → `QMenu::timerEvent()`. Qt doesn't take into account the possibility of dangling pointers in `qmenu.cpp` under very rare circumstances, e.g., when the actions of a menu with a visible submenu are recreated too rapidly multiple times (also see https://bugreports.qt.io/browse/QTBUG-77273, although our case is much more complex). That may no be unexpected in a code full of timers and event handling. To avoid dangling pointers, the patch just puts a minimum interval of two seconds between two consecutive reloads. It also restores the active action on refreshing, such that a reloaded submenu isn't closed anymore (see lxqt/lxqt#2282 and especially @yan12125's report https://gitlab.gnome.org/GNOME/network-manager-applet/-/issues/195). Finally, it removes a redundant, recursive computation. Closes lxqt/lxqt-panel#1802 NOTE: I was able to reproduce the crash easily with nm-applet. Before arriving at this workaround, I tried various ideas but could still make lxqt-panel crash in a few minutes. Only this time I can't, in spite of trying for days.
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Such random crashes are triggered by Qt →
QMenu::timerEvent(). Qt doesn't take into account the possibility of dangling pointers inqmenu.cppunder very rare circumstances, e.g., when the actions of a menu with a visible submenu are recreated too rapidly multiple times (also see https://bugreports.qt.io/browse/QTBUG-77273, although our case is much more complex). That may no be unexpected in a code full of timers and event handling.To avoid dangling pointers, the patch just puts a minimum interval of two seconds between two consecutive reloads.
It also restores the active action on refreshing, such that a reloaded submenu isn't closed anymore (see lxqt/lxqt#2282 and especially @yan12125's report https://gitlab.gnome.org/GNOME/network-manager-applet/-/issues/195).
Finally, it removes a redundant, recursive computation.
Closes lxqt/lxqt-panel#1802
NOTE: I was able to reproduce the crash easily with nm-applet. Before arriving at this workaround, I tried various ideas but could still make lxqt-panel crash in a few minutes. Only this time I can't, in spite of trying for days.