During a VT-Switch a raw pointer to the shared cursor object
is saved which is then freed (in case of low refcount) by a call to
xf86CursorSetCursor with argument pCurs = NullCursor.
This leads to a dangling pointer which can follow in a use after free.
This fix ensures that there is a shared handle saved for the VT-Switch cycle.
Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
(cherry picked from commit 7ae221ad57)
c726ceacc1