[v4] Fix strptime era handling, add more era tests [BZ #24394]

[Carlos O'Donell]

On 3/29/19 1:58 PM, DJ Delorie wrote:
> TAMUKI Shoichi <tamuki@linet.gr.jp> writes:
>> This test case is intended to check whether strptime can correctly
>> parse %EY, so it would be nice to rename it to tst-strptime4.c.
> 
> The test case was originally written to further test the strftime
> handling of the upcoming era change, but I don't care what the name of
> the test is ;-)
> 
> I added the strptime check "just because" and only found the strptime
> bug after that.
> 
>> The test case to check whether strftime can correctly format %EY
>> already exists as tst-strftime2.c.
> 
> Yup, this is an additional test.
> 
> I see no harm in having overlapping test coverage, especially if the
> tests approach the problem in different ways.  New coverage can be added
> to whichever test the submitter finds more comfortable editing, too.
> Personally, I'm not a fan of logic-driven test data.  I prefer
> table-driven since I don't need to worry as much about bugs in the test
> itself, and it's easier to list unusual test cases than try to encode
> them in logic.
  
.. and tst-strftime2.c is hideous, a terrible test with no comments
whose logic cannot be followed.

I suggest keeping the test named tst-strftime3.c.

Eventually I hope we move the tst-strftime2.c tests to the new test
and remove the old test.

-- 
Cheers,
Carlos.