Change 34209: [perl #56908] DBI memory leak in 5.10.0 due to change 26530

[Dave Mitchell]

Change 34209 by [EMAIL PROTECTED] on 2008/08/20 23:15:36

         [perl #56908] DBI memory leak in 5.10.0 due to change 26530
        
         A weakref to a HV would leak, because the xhv_backreferences
         array is created with a refcount of 2 (to avoid premature freeing
         during global destruction), but the RC was only decremented once
         when the parent HV was freed.
         Also, when thread cloned, the new array was being created with a
         RC of 1, rather than 2, which coincidentally worked due to the
         first bug.

Affected files ...

... //depot/perl/hv.c#377 edit
... //depot/perl/sv.c#1549 edit

Differences ...

==== //depot/perl/hv.c#377 (text) ====
Index: perl/hv.c
--- perl/hv.c#376~34190~        2008-08-09 03:04:55.000000000 -0700
+++ perl/hv.c   2008-08-20 16:15:36.000000000 -0700
@@ -1985,6 +1985,7 @@
     if (av) {
        HvAUX(hv)->xhv_backreferences = 0;
        Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
+       SvREFCNT_dec(av);
     }
 }
 

==== //depot/perl/sv.c#1549 (text) ====
Index: perl/sv.c
--- perl/sv.c#1548~34144~       2008-07-15 07:51:53.000000000 -0700
+++ perl/sv.c   2008-08-20 16:15:36.000000000 -0700
@@ -10784,10 +10784,11 @@
                        daux->xhv_eiter = saux->xhv_eiter
                            ? he_dup(saux->xhv_eiter,
                                        (bool)!!HvSHAREKEYS(sstr), param) : 0;
+                       /* backref array needs refcnt=2; see sv_add_backref */
                        daux->xhv_backreferences =
                            saux->xhv_backreferences
                                ? (AV*) SvREFCNT_inc(
-                                       sv_dup((SV*)saux->xhv_backreferences, 
param))
+                                       
sv_dup_inc((SV*)saux->xhv_backreferences, param))
                                : 0;
 
                         daux->xhv_mro_meta = saux->xhv_mro_meta
End of Patch.