Better ithreads cloning - add all SVs with a 0 refcnt to the temps stack.

Track all SVs created by sv_dup() that have a 0 reference count. If they still
have a 0 reference count at the end of cloning, assign a reference to each to
the temps stack. As the temps stack is cleared at thread exit, SVs book keeping
will be correct and consistent before perl_destruct() makes its check for
leaked scalars.

Remove special case code for checking each @_ and the parent's temp stack.

1 files changed, 11 insertions, 1 deletions

diff --git a/t/op/threads.t b/t/op/threads.t
index d9fed9b6fe..364045d995 100644
--- a/t/op/threads.t
+++ b/t/op/threads.t
@@ -16,7 +16,7 @@ BEGIN {
        exit 0;
      }
 
-     plan(19);
+     plan(20);
 }
 
 use strict;
@@ -253,4 +253,14 @@ fresh_perl_like(<<'EOI', qr/\AThread 1 terminated abnormally: Not a CODE referen
     print "end";
 EOI
 
+fresh_perl_is(<<'EOI', 'ok', { }, '0 refcnt neither on tmps stack nor in @_');
+    use threads;
+    my %h = (1, []);
+    use Scalar::Util 'weaken';
+    my $a = $h{1};
+    weaken($a);
+    delete $h{1} && threads->create(sub {}, shift)->join();
+    print 'ok';
+EOI
+
 # EOF