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

[TAMUKI Shoichi]

Hello Carlos-san,

From: Carlos O'Donell <codonell@redhat.com>
Subject: Re: [v4] Fix strptime era handling, add more era tests [BZ #24394]
Date: Fri, 29 Mar 2019 10:53:09 -0400

> > The test case to check whether strftime can correctly format %EY
> > already exists as tst-strftime2.c.  This covers ja_JP, lo_LA, th_TH,
> > zh_TW, cmn_TW, hak_TW, nan_TW, and lzh_TW.  Regarding *_TW, Rafal-san
> > is preparing a patch.
> 
> The *most important* thing for me is that ja_JP get coverage of the
> possible interface uses for the upcoming era name change.
> 
> I suggest we focus *only* on ja_JP locale today, and get the new test
> in place to test the April 1st new era name change.

Agreed.

> > In addition to ja_JP locale, I think it is necessary to check the
> > locale of other countries, in particular *_TW locale.
> 
> Agreed. We can add these later.
>   
> > What about the consideration of %EY, %_EY, and %-EY?
> 
> Agreed. We can add these later.
> 
> For now I think testing %EY is the single most useful thing, and I
> think we could accept the patch just for that.

Agreed.

> > How does it behave if specifying a non-existent date, such as:
> > 
> > Heisei gan nen 01 gatsu 07 nichi
> > Showa   64 nen 01 gatsu 08 nichi
> > 
> > I think that these tests are also necessary.
> 
> As Rafal points out I think we could use your help there. If we
> accept DJ's patch then you could work on top of that to add a few
> more test cases to check invalid tests?

Yes, I can contribute as needed.  Since it is expected that the
response to the new era of some systems is delayed, I think that there
is a case to parse non-existent date.  According to the Japanese
government, the use of "H31.5.1", "H31.8.12", etc. are permitted for a
certain period of time.

Regards,
TAMUKI Shoichi