Re: [PATCH] fix printf regression with alt-form octal, default precision

[Rich Felker <dalias@libc.org>]

On Thu, Sep 15, 2016 at 07:04:34PM +0300, Dmitry V. Levin wrote:
> Ping?
> 
> On Thu, Aug 04, 2016 at 04:07:40AM +0300, Dmitry V. Levin wrote:
> > commit v1.1.5-10-gb91cdbe2bc8b626aa04dc6e3e84345accf34e4b1 that fixed
> > behavior of printf with alt-form octal, zero precision, zero value,
> > at the same time broke alt-form octal with default precision,
> > e. g. printf("%#09o", 1).
> > ---
> >  src/stdio/vfprintf.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> > 
> > diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
> > index 2ecf769..ac2891c 100644
> > --- a/src/stdio/vfprintf.c
> > +++ b/src/stdio/vfprintf.c
> > @@ -570,7 +570,14 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
> >  			if (0) {
> >  		case 'o':
> >  			a = fmt_o(arg.i, z);
> > -			if ((fl&ALT_FORM) && p<z-a+1) p=z-a+1;
> > +			if (fl&ALT_FORM) {
> > +				if (p >= 0 && p<z-a+1) {
> > +					p=z-a+1;
> > +				} else if (arg.i) {
> > +					prefix+=5;
> > +					pl=1;
> > +				}
> > +			}

This still does not fix all cases, e.g. printf("%#09.0o\n", 0);

I'm going to try to understand what's going on and make a complete
fix.

Rich