When refreshing a QDateTime(,, Qt::LocalTime) we call mktime on data obtained from it, passing in the DST status (when known; this keeps two otherwise identical times in a fall-back distinct). One of the tests relies on changing zone under the feet of such a date-time, created in Hawaiian standard time; it serializes it, the reads it back in Western Australian Daylight-saving time and expects the results to be equal. However, the two differ in DST-ness, which leads to mktime() failing for the Hawaiian original, with unwelcome results. Notice this case, failure with DST-ness claimed known, and retry without the claim, so as to correct the DST-ness. Change-Id: Id0278df53130f76fc587769efe946ca9af1adc26 Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>