WidgetsAskUserActionHandler: create message dialog in the main thread
In Qt, the GUI runs in its own thread and must be accessed from the main thread. If QWidget is created in a non-main thread, we can use the QMetaObject::invokeMethod() method to create it in the main thread. This fixes a crash in plasmashell where there is no active QWidget window.
BUG: 465454 FIXED-IN: 5.106
Edited by Fushan Wen