While investigating an assertion failure I noticed that the existing
tests didn't even exercise these methods for local time or zone time.
Of course, we can't robustly test these time-specs, due to vagueries
of offset details and zone availability, but we can at least verify
that they return date-times on the specified date. Add a test-case for
the start of 1900, on which the assertions were first seen; it is the
earliest moment representable with tm_year >= 0, after all.
One of these tests fails on 6.2 but the fix for that (as opposed to
the the assertion) requires 6.3's improvements to the handling of
time_t's fuller range - too risky a change to pick back to 6.2.
Pick-to: 6.3
Task-number: QTBUG-99747
Change-Id: I98f5d7850a701972b2d8ea2ce203a2b3e7071354
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
830fd1908b