pp_undef was not always freeing memory

As I found, pp_undef in
	$a = 'aaa';
	$a = 0;
	undef $a;
was not reclaiming the storage, as it does in
        $a = 'aaa';
        undef $a;

The patch is below fixes this shortcoming (tests ok, perl rebuilds
itself OK),

Enjoy,

p5p-msgid: <199702270707.CAA13978@monk.mps.ohio-state.edu>
private-msgid: <199702270653.BAA13949@monk.mps.ohio-state.edu>

1 files changed, 1 insertions, 1 deletions

diff --git a/pp.c b/pp.c
index 62a01ec5ae..0e924a35ce 100644
--- a/pp.c
+++ b/pp.c
@@ -555,7 +555,7 @@ PP(pp_undef)
 	    sv_setsv(sv, &sv_undef);
 	break;
     default:
-	if (SvPOK(sv) && SvLEN(sv)) {
+	if (SvTYPE(sv) >= SVt_PV && SvPVX(sv) && SvLEN(sv)) {
 	    (void)SvOOK_off(sv);
 	    Safefree(SvPVX(sv));
 	    SvPV_set(sv, Nullch);