Hi Jan

I ran make command in regress/lib/libc/print and got success.

ok asou@
--
ASOU Masato


On Wed, Sep 16, 2026 at 12:06 PM Jan Klemkow <jan@openbsd.org> wrote:

> On Mon, Sep 14, 2026 at 07:50:18PM +0900, 蟹澤翔太 wrote:
> > Thanks for the quick reply.  Of the three you named, the kernel copy
> > has the same bug; the other two don't.
> >
> > sys/kern/subr_prf.c (kprintf) is not shrunk in this respect -- it has
> > the same code as libc, the "if (_uquad != 0 || prec != 0)" test with
> > the octal leading-0 step inside it, so "%#.0o" of 0 prints nothing
> > there too.  Diff below.
> >
> > sys/lib/libsa/printf.c (bootblocks) is shrunk past where it matters:
> > no precision and no # handling for octal, so "%#.0o" can't reach the
> > bug -- the flag is ignored and it prints the digits.
> >
> > libexec/ld.so/util.c (_dl_printf) is the same: no precision, no #,
> > nothing to fix.
> >
> > I only looked at those three, not the whole tree.
> >
> > I built GENERIC.MP with the diff -- it compiles clean.  Pulling the
> > octal block out of subr_prf.c into a small harness, the stock code
> > prints [] for "%#.0o" of 0 and the patched code prints [0]; "%#.0o" of
> > 8 -> [010], "%.0o" of 0 -> [], and "%#o" of 0 -> [0] are unchanged
> > either way.  Same one-line change I made in libc, built on 7.9 and
> > checked the same way.
> >
> > > 2026/09/11 10:13、Theo de Raadt <deraadt@openbsd.org>のメール:
> > >
> > > Please check for other clones of printf in the tree.  There is one
> > > in kernel, one in bootblocks, one in ld.so.  There may be others.
> > > These have all been shrunk, but maybe it matters.
>
> Hi Showta,
>
> Thanks for you diff.  Finally Defect Report #151 [0] gets fixed in
> OpenBSD.  I just warped the long lines and adds a regression test in
> the diff below.
>
> ok?
>
> [0]: https://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_151.html
>
> Thanks,
> jan
>
> Index: lib/libc/stdio/vfprintf.c
> ===================================================================
> RCS file: /cvs/src/lib/libc/stdio/vfprintf.c,v
> diff -u -p -r1.84 vfprintf.c
> --- lib/libc/stdio/vfprintf.c   8 Aug 2025 15:58:53 -0000       1.84
> +++ lib/libc/stdio/vfprintf.c   16 Sep 2026 17:26:07 -0000
> @@ -923,9 +923,13 @@ number:                    if ((dprec = prec) >= 0)
>                          * ``The result of converting a zero value with an
>                          * explicit precision of zero is no characters.''
>                          *      -- ANSI X3J11
> +                        *
> +                        * The # flag overrides that for octal: it asks
> for a
> +                        * leading zero, so "%#.0o" of 0 is "0", not "".
>                          */
>                         cp = buf + BUF;
> -                       if (_umax != 0 || prec != 0) {
> +                       if (_umax != 0 || prec != 0 ||
> +                           (flags & ALT && base == OCT)) {
>                                 /*
>                                  * Unsigned mod is hard, and unsigned mod
>                                  * by a constant is easier than that by
> Index: lib/libc/stdio/vfwprintf.c
> ===================================================================
> RCS file: /cvs/src/lib/libc/stdio/vfwprintf.c,v
> diff -u -p -r1.25 vfwprintf.c
> --- lib/libc/stdio/vfwprintf.c  8 Aug 2025 15:58:53 -0000       1.25
> +++ lib/libc/stdio/vfwprintf.c  16 Sep 2026 17:26:07 -0000
> @@ -901,9 +901,13 @@ number:                    if ((dprec = prec) >= 0)
>                          * ``The result of converting a zero value with an
>                          * explicit precision of zero is no characters.''
>                          *      -- ANSI X3J11
> +                        *
> +                        * The # flag overrides that for octal: it asks
> for a
> +                        * leading zero, so "%#.0o" of 0 is "0", not "".
>                          */
>                         cp = buf + BUF;
> -                       if (_umax != 0 || prec != 0) {
> +                       if (_umax != 0 || prec != 0 ||
> +                           (flags & ALT && base == OCT)) {
>                                 /*
>                                  * Unsigned mod is hard, and unsigned mod
>                                  * by a constant is easier than that by
> Index: regress/lib/libc/printf/int.c
> ===================================================================
> RCS file: /cvs/src/regress/lib/libc/printf/int.c,v
> diff -u -p -r1.2 int.c
> --- regress/lib/libc/printf/int.c       14 Jul 2020 16:40:04 -0000      1.2
> +++ regress/lib/libc/printf/int.c       16 Sep 2026 17:26:07 -0000
> @@ -326,6 +326,7 @@ main(int argc, char *argv[])
>
>         tu("<%hho>", S_CHAR, 0, "<0>");
>         tu("<%#hho>", S_CHAR, 0, "<0>");
> +       tu("<%#.0hho>", S_CHAR, 0, "<0>");
>         tu("<%hho>", S_CHAR, UINT8_MAX, "<377>");
>         tu("<%#hho>", S_CHAR, UINT8_MAX, "<0377>");
>         tu("<%hho>", S_CHAR, -1, "<377>");
> Index: sys/kern/subr_prf.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/subr_prf.c,v
> diff -u -p -r1.106 subr_prf.c
> --- sys/kern/subr_prf.c 14 Aug 2022 01:58:28 -0000      1.106
> +++ sys/kern/subr_prf.c 16 Sep 2026 17:42:19 -0000
> @@ -960,7 +960,8 @@ number:                     if ((dprec = prec) >= 0)
>                          *      -- ANSI X3J11
>                          */
>                         cp = buf + KPRINTF_BUFSIZE;
> -                       if (_uquad != 0 || prec != 0) {
> +                       if (_uquad != 0 || prec != 0 ||
> +                           (flags & ALT && base == OCT)) {
>                                 /*
>                                  * Unsigned mod is hard, and unsigned mod
>                                  * by a constant is easier than that by
>
>