Component.onDestruction can be used to execute some code as an object is
being destructed. The code may, however, reference objects that are no
longer in a valid state because they themselves have already been
destructed. We then throw an exeception.
Commit a741271dd5 introduced the init step
for calls in which the types of arguments are resolved. For object
methods, we need to check that the object is still valid or throw an
exception otherwise. This is made more complicated by the fact that, in
some cases, the destruction of the object happens in a somewhat chaotic
manner where, for instance, the object is still alive but its method and
property storage has already been deleted.
This inconsistent state is the cause of QTBUG-138516 and existing checks
for invalid objects were not sufficient and we crashed when trying to
use the function that we were unable to resolve. We can detect this
particular problem by checking whether the ddata of the object still has
its jsWrapper.
Amends a741271dd5
Fixes: QTBUG-138516
Pick-to: 6.10 6.9
Change-Id: Ifdd7708d73ea6012d1e07aebed257b3f538183c1
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Olivier De Cannière