From: Nicholas Clark <nick@ccl4.org>
Date: Wed, 1 Jun 2005 15:23:02 +0000 (+0000)
Subject: Zero-ing the new HV array is pointless, as we write to every element.
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=a1cfa1c67270cd04b1ea57513e32792eca6c3d2b;p=p5sagit%2Fp5-mst-13.2.git

Zero-ing the new HV array is pointless, as we write to every element.
Also avoid calling into he_dup when the HE is 0, to save the function
call overhead.

p4raw-id: //depot/perl@24662
---

diff --git a/sv.c b/sv.c
index 33584a3..30aa440 100644
--- a/sv.c
+++ b/sv.c
@@ -10926,18 +10926,18 @@ Perl_sv_dup(pTHX_ SV *sstr, CLONE_PARAMS* param)
 
 	    if (HvARRAY((HV*)sstr)) {
 		STRLEN i = 0;
+		bool sharekeys = !!HvSHAREKEYS(sstr);
 		XPVHV *dxhv = (XPVHV*)SvANY(dstr);
 		XPVHV *sxhv = (XPVHV*)SvANY(sstr);
 		char *darray;
-		/* FIXME - surely this doesn't need to be zeroed?  */
-		Newz(0, darray,
+		New(0, darray,
 		     PERL_HV_ARRAY_ALLOC_BYTES(dxhv->xhv_max+1)
 		     + (SvOOK(sstr) ? sizeof(struct xpvhv_aux) : 0), char);
 		HvARRAY(dstr) = (HE**)darray;
 		while (i <= sxhv->xhv_max) {
+		    HE *source = HvARRAY(sstr)[i];
 		    HvARRAY(dstr)[i]
-			= he_dup(HvARRAY(sstr)[i],
-				 (bool)!!HvSHAREKEYS(sstr), param);
+			= source ? he_dup(source, sharekeys, param) : 0;
 		    ++i;
 		}
 		if (SvOOK(sstr)) {