SCALAR/FIRSTKEY for tied hashes in scalar context

Message-id: <20031206105059.GA13989@ethan>

p4raw-id: //depot/perl@21855

1 files changed, 41 insertions, 0 deletions

diff --git a/mg.c b/mg.c
index 3e864da30b..2529ff7793 100644
--- a/mg.c
+++ b/mg.c
@@ -1538,6 +1538,12 @@ Perl_magic_wipepack(pTHX_ SV *sv, MAGIC *mg)
     call_method("CLEAR", G_SCALAR|G_DISCARD);
     POPSTACK;
     LEAVE;
+
+    if (SvTYPE(sv) == SVt_PVHV)
+        /* must reset iterator otherwise Perl_magic_scalarpack
+         * wont report a false value on a cleared hash */
+        HvEITER((HV*)sv) = NULL;
+    
     return 0;
 }
 
@@ -1572,6 +1578,41 @@ Perl_magic_existspack(pTHX_ SV *sv, MAGIC *mg)
     return magic_methpack(sv,mg,"EXISTS");
 }
 
+SV *
+Perl_magic_scalarpack(pTHX_ HV *hv, MAGIC *mg)
+{
+    dSP;
+    SV *retval = &PL_sv_undef;
+    SV *tied = SvTIED_obj((SV*)hv, mg);
+    HV *pkg = SvSTASH((SV*)SvRV(tied));
+   
+    if (!gv_fetchmethod_autoload(pkg, "SCALAR", FALSE)) {
+        SV *key;
+        if (HvEITER(hv))
+            /* we are in an iteration so the hash cannot be empty */
+            return &PL_sv_yes;
+        /* no xhv_eiter so now use FIRSTKEY */
+        key = sv_newmortal();
+        magic_nextpack((SV*)hv, mg, key);
+        HvEITER(hv) = NULL;     /* need to reset iterator */
+        return SvOK(key) ? &PL_sv_yes : &PL_sv_no;
+    }
+   
+    /* there is a SCALAR method that we can call */
+    ENTER;
+    PUSHSTACKi(PERLSI_MAGIC);
+    PUSHMARK(SP);
+    EXTEND(SP, 1);
+    PUSHs(tied);
+    PUTBACK;
+
+    if (call_method("SCALAR", G_SCALAR))
+        retval = *PL_stack_sp--; 
+    POPSTACK;
+    LEAVE;
+    return retval;
+}
+
 int
 Perl_magic_setdbline(pTHX_ SV *sv, MAGIC *mg)
 {