[Bug libstdc++/39168] Incorrect interpretation of CHAR_MAX inside grouping string in monetary and numeric facets.

[tsyvarev at ispras dot ru]

------- Comment #7 from tsyvarev at ispras dot ru  2009-02-13 11:21 -------
(In reply to comment #4)
> 
> I'm not sure I understand your rationale or I agree that this is a bug. IIUC,
> string(1, CHAR_MAX) indicates that groups may be of arbitrary length, which
> includes "123,456" This behavior is the same regardless of whether char is
> a signed or unsigned type.

"Arbitrary length" is not quite correct here - "123,456" violates grouping,
given with string(1, CHAR_MAX). Standard use term "unlimited length", which
means(as I understand) that all other digits should incorporate in only one
group - only "123456" is correct.

(In reply to comment #6)
>Actually, libstdc++ stores 123456, which is indeed fine, and sets failbit |
>eofbit, failbit exactly because of the issue discussed here.

The thing is that, according to the standard, CHAR_MAX should be treats similar
as -1. But implementation treats string(1, -1) as no grouping at all, and stops
read, when has encountered symbol ','. So only "123" is accumulated.
This behaviour seems correct for me (though standard treats only string() as no
grouping at all, 22.2.2.1.2, p8).
So with string(1, CHAR_MAX) only "123" should be accumulated, not "123,456".

In other words, test is passed when CHAR_MAX is replaced with -1. Inside
grouping string, CHAR_MAX means same as -1(according to the standard). So test
should be passed with original text.

The same is about the second test.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39168