Chart the self-tying minefield.

[perl5.git] / sv.c

diff --git a/sv.c b/sv.c
index 5992a69..18fdfc1 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -4461,16 +4461,20 @@ Perl_sv_magicext(pTHX_ SV* sv, SV* obj, int how, MGVTBL *vtable,
     /* Some magic sontains a reference loop, where the sv and object refer to
        each other.  To prevent a reference loop that would prevent such
        objects being freed, we look for such loops and if we find one we
-       avoid incrementing the object refcount. */
+       avoid incrementing the object refcount.
+
+       Note we cannot do this to avoid self-tie loops as intervening RV must
+       have its REFCNT incremented to keep it in existence - instead we could
+       special case them in sv_free() -- NI-S
+
+    */
     if (!obj || obj == sv ||
        how == PERL_MAGIC_arylen ||
        how == PERL_MAGIC_qr ||
        (SvTYPE(obj) == SVt_PVGV &&
            (GvSV(obj) == sv || GvHV(obj) == (HV*)sv || GvAV(obj) == (AV*)sv ||
            GvCV(obj) == (CV*)sv || GvIOp(obj) == (IO*)sv ||
-           GvFORM(obj) == (CV*)sv)) ||
-       (how == PERL_MAGIC_tiedscalar &&
-           SvROK(obj) && (SvRV(obj) == sv || GvIO(SvRV(obj)) == (IO*)sv)))
+           GvFORM(obj) == (CV*)sv)))
     {
        mg->mg_obj = obj;
     }
@@ -6338,7 +6342,7 @@ Perl_newSVpvn_share(pTHX_ const char *src, I32 len, U32 hash)
        len = tmplen;
     }
     if (!hash)
-       PERL_HASH(hash, (U8*)src, len);
+       PERL_HASH(hash, src, len);
     new_SV(sv);
     sv_upgrade(sv, SVt_PVIV);
     SvPVX(sv) = sharepvn(src, is_utf8?-len:len, hash);
@@ -9711,7 +9715,7 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PERL_SET_THX(my_perl);
 
 #  ifdef DEBUGGING
-    memset(my_perl, 0xab, sizeof(PerlInterpreter));
+    Poison(my_perl, 1, PerlInterpreter);
     PL_markstack = 0;
     PL_scopestack = 0;
     PL_savestack = 0;
@@ -9742,7 +9746,7 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 
 
 #    ifdef DEBUGGING
-    memset(my_perl, 0xab, sizeof(PerlInterpreter));
+    Poison(my_perl, 1, PerlInterpreter);
     PL_markstack = 0;
     PL_scopestack = 0;
     PL_savestack = 0;