stringify looses integerness

Gurusamy Sarathy <gsar@engin.umich.edu> writes:

> On 01 Jul 1997 20:49:15 +0200, Gisle Aas wrote:
> >The following patch (relative to perl5.004) makes this bug go away.
> >Perl still passes all it's tests and the original example works as it
> >did in perl5.003.
> >
> >--- sv.c.orig   Tue Jul  1 20:26:40 1997
> >+++ sv.c        Tue Jul  1 20:38:13 1997
> >@@ -1713,6 +1713,7 @@
> >            sv_upgrade(sv, SVt_PVIV);
> >        olderrno = errno;       /* some Xenix systems wipe out errno here */
> >        sv_setpvf(sv, "%Vd", SvIVX(sv));
> >+       SvIOK_on(sv);  /* it is still valid */
> >        errno = olderrno;
> >        s = SvEND(sv);
> >     }
>
> That should restore precisely those flags that were active
> before sv_setpvf() was called. eg: the case where {pIOK,NOK,pNOK}
> are set, the resulting SV should have {pPOK,POK,pIOK,NOK,pNOK}
> set.

NOK or pNOK can't be set at this point.  The only possibility is that
pIOK is set and not IOK (but I don't know how can I trigger this
condition?)

This patch should then be safer (it also passes all tests):

p5p-msgid: hbu4l96z2.fsf@bergen.sn.no

diff --git a/sv.c b/sv.c
index 53499fd..ce85a4b 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -1710,12 +1710,17 @@ STRLEN *lp;
 #endif
     }
     else if (SvIOKp(sv)) {
+       U32 oldIOK = SvIOK(sv);
        if (SvTYPE(sv) < SVt_PVIV)
            sv_upgrade(sv, SVt_PVIV);
        olderrno = errno;       /* some Xenix systems wipe out errno here */
        sv_setpvf(sv, "%Vd", SvIVX(sv));
        errno = olderrno;
        s = SvEND(sv);
+       if (oldIOK)
+           SvIOK_on(sv);
+       else
+           SvIOKp_on(sv);
     }
     else {
        if (dowarn && !localizing && !(SvFLAGS(sv) & SVs_PADTMP))