I32 preeminent = 0;
if (SvTYPE(hv) == SVt_PVHV) {
- if (PL_op->op_private & OPpLVAL_INTRO)
- preeminent = SvRMAGICAL(hv) ? 1 : hv_exists_ent(hv, keysv, 0);
+ if (PL_op->op_private & OPpLVAL_INTRO) {
+ MAGIC *mg;
+ HV *stash;
+ /* does the element we're localizing already exist? */
+ preeminent =
+ /* can we determine whether it exists? */
+ ( !SvRMAGICAL(hv)
+ || mg_find((SV*)hv, PERL_MAGIC_env)
+ || ( (mg = mg_find((SV*)hv, PERL_MAGIC_tied))
+ /* Try to preserve the existenceness of a tied hash
+ * element by using EXISTS and DELETE if possible.
+ * Fallback to FETCH and STORE otherwise */
+ && (stash = SvSTASH(SvRV(SvTIED_obj((SV*)hv, mg))))
+ && gv_fetchmethod_autoload(stash, "EXISTS", TRUE)
+ && gv_fetchmethod_autoload(stash, "DELETE", TRUE)
+ )
+ ) ? hv_exists_ent(hv, keysv, 0) : 1;
+
+ }
he = hv_fetch_ent(hv, keysv, lval && !defer, hash);
svp = he ? &HeVAL(he) : 0;
}