The format is changed from 6.7 to support more than UINT32_MAX - 1
elements. The format used to have a quint32 size. Now if the size is
larger or equal to 0xfffffffe (2^32 -2) the old size is an extend
value 0xfffffffe followed by one quint64 with the actual value. The
32 bit size with all bits set is still used as null value.
Fixes: QTBUG-105034
Change-Id: I62188be170fe779022ad58ab84a54b1eaf46e5d9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
fd48ce0b73