Use QPromise when creating continuations to avoid memory leaks

Continuations were using QFutureInterface to create and return the
associated future to the user. Attaching a continuation to the returned
future could cause memory leaks (described in an earlier commit). Use a
QPromise when saving the continuation, to make sure that the attached
continuation is cleaned in the destructor of the associated QPromise, so
that it doesn't keep any ref-counted copies to the shared data, thus
preventing it from being deleted.

Task-number: QTBUG-99534
Pick-to: 6.3 6.2
Change-Id: I52d5501292095d41d1e060b7dd140c8e5d01335c
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

0 files changed, 0 insertions, 0 deletions