winsup/cygwin/libc/strptime.cc(__strptime) strptime %F issue
Corinna Vinschen
corinna-cygwin@cygwin.com
Thu Aug 24 20:01:00 GMT 2017
On Aug 24 11:32, Corinna Vinschen wrote:
> On Aug 23 13:25, Brian Inglis wrote:
> > Cygwin strptime(3) (also strptime(1)) fails with default width, without an
> > explicit width, because of the test in the following code:
> >
> > case 'F': /* The date as "%Y-%m-%d". */
> > {
> > LEGAL_ALT(0);
> > ymd |= SET_YMD;
> > char *tmp = __strptime ((const char *) bp, "%Y-%m-%d",
> > tm, era_info, alt_digits,
> > locale);
> > if (tmp && (uint) (tmp - (char *) bp) > width)
> > return NULL;
> > bp = (const unsigned char *) tmp;
> > continue;
> > }
> >
> > as default width is zero so test fails and returns NULL.
> >
> > Simple patch for this as with the other cases supporting width is to change the
> > test to:
> >
> > if (tmp && width && (uint) (tmp - (char *) bp) > width)
> >
> > but this does not properly support [+0] flags or width in the format as
> > specified by glibc (latest POSIX punts on %F) for compatibility with strftime(),
> > affecting only the %Y format, supplying %[+0]<w-6>F, to support signed and zero
> > filled fixed and variable length year fields in %F format.
>
> Ok, I admit I didn't understand this fully. What is '<w-6>'?
> Can you give a real world example?
>
> > So do you want compatible support or just the quick fix?
>
> Quick and then right? Fixing this in two steps is just as well.
Btw., FreeBSD's _strptime only calls _strptime recursively, without any
checks for field width:
case 'F':
buf = _strptime(buf, "%Y-%m-%d", tm, GMTp, locale);
if (buf == NULL)
return (NULL);
flags |= FLAG_MONTH | FLAG_MDAY | FLAG_YEAR;
break;
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
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