For the following tzdb entry(tzdata2014a) the GMT offset change time is calculated incorrectly:
Zone Europe/Istanbul 1:55:52 - LMT 1880
                        1:56:56 - IMT 1910 Oct # Istanbul Mean Time?
                        2:00 Turkey EE%sT 1978 Oct 15
                        3:00 Turkey TR%sT 1985 Apr 20 # Turkey Time
                        2:00 Turkey EE%sT 2007
                        2:00 EU EE%sT 2011 Mar 27 1:00u
                        2:00 - EET 2011 Mar 28 1:00u
                        2:00 EU EE%sT 2014 Mar 30 1:00u
                        2:00 - EET 2014 Mar 31 1:00u
                        2:00 EU EE%sT

The test class reports that there will be a future GMT raw offset change on "2014 Mar 31", but the raw GMT offset is not changing since "1985 Apr 20".
The following test implementation error cause the test failure with latest tzdata (2014a):
    Europe/Istanbul : Europe/Istanbul
offset=7200000,dstSavings=3600000,useDaylight=true,transitions=171,offsets=5,checksum=-508379603,gmtChanged=false
[NG]offset=7200000,dstSavings=3600000,useDaylight=true,transitions=171,offsets=5,checksum=-508379603,gmtChanged=true