The stream in question is from prior to Qt 5.0 release, before
commit 718a2251be changed QDateTime
serialization format to store Qt::TimeSpec instead of the private
flag. The last byte was 0xff meaning LocalUnknown, but 0xff is
not valid in Qt 5.0.
It was just garbage that Qt up to now just accepted. With the upcoming
short QDateTime optimization, the results are worse.
Change-Id: I25d85d86649448d5b2b3fffd1450f57df17e7794
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@theqtcompany.com>