KGlobalAccel plugin gets deleted by a global static. At that point
InputRedirection is already deleted but the plugin holds a static pointer
to it.
This change connects to the deleted signal by InputRedirection and
ensures that the plugin doesn't call into the deleted code any more.
The KGlobalAccelD which gets created by KWin needs a plugin for the
platform specific parts. This change introduces such a plugin. It's
linked against kwin so that it can integrate with the core.
On enable the plugin registers itself in the InputRedirection and
GlobalShortcutsManager checks the plugin whether a shortcut got
triggered.
As the loading of the plugin must happen after InputRedirection is
fully created a dedicated init method is added to InputRedirection.
REVIEW: 124187
