The fix is trivial, but the patch adds a new QSettings tests that iterates most
of the QMetaTypes and verifies that storing and retrieving them again gives the
same value. This is a more complete test than the testVariantTypes tests, which
is limited to a subset of the QVariant types. The new tests borrows logic from
the QMetaType test machinery.
QSettings has been Q_ENUM'ified in the process, for improved debug output.
Note that on backends such as the INI backend, the metatype of the QVariant read
from the settings will be a string, so it won't match the input QVariant type,
but the result of converting that to the original value type should still work.
Task-number: QTBUG-56124
Change-Id: Ib03a26abf77c9fb449b94160d28bc4baeb095f25
Reviewed-by: Jake Petroules <jake.petroules@qt.io>