Europe/Samara reduced its standard offset at the same time as it
started DST in March 2010, so the transition didn't change net offset.
Our interpretation of the TZ database assumed the prior standard
offset still applied; as this was equal to the new offset with DST, it
marked the dst offset as zero, so we interpreted the next few months
as being without DST, although the TZ database marks it as with.
Generally, if a DST period has an odd DST offset, it's possible it's
due to a change to standard offset at its start. Deem the offset odd
if it's not what we last saw (or, on the first DST, not an hour); in
that case, check the DST period's end, to see if it offers a less odd
DST offset. Positive DST offsets are less odd than zero or negative;
otherwise, expect what we saw last, one hour is not odd and closer to
what we saw last is less odd than further from it. This suffices to
fix Samara in 2010, at least.
Task-number: QTBUG-56345
Change-Id: I9f0ee4e9cd6901c28a8ec1558aec5d26a21152f6
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
772b12c436