calling a javascript function from python, with a javascript argument that contains a python object, leads to that python object not being freed

```
What steps will reproduce the problem?
Run the following code:

import weakref
import gc

import PyV8

tracks = {} #map weakref id to (weakref, description)
def tracked_deleted(r):
_, descr = tracks[id(r)]
print ("Tracked object '%s' just deleted." % (descr,))
del tracks[id(r)]
def track(o, descr=""):
r = weakref.ref(o, tracked_deleted)
tracks[id(r)] = (r, "%s:%s" % (o.__class__.__name__, descr))
return o

class PyObj(object):
def __init__(self, name):
track(self, name)

class Global(object):
def Obj(self, name):
return PyObj(name)

def callWith(self, blah, f):
f(blah)

def run_case(name, js, cleanup):
print "\nCase %s:" % (name,)
ctxt = PyV8.JSContext(Global())

with ctxt:
ctxt.eval(js)

print " V8 cleanup"
ctxt.eval(cleanup)
print " V8 gc"
PyV8.JSEngine.collect()
print " Py gc"
gc.collect()
print " V8 gc"
PyV8.JSEngine.collect()
print " Py gc"
gc.collect()
print " Py gc.garbage:", gc.garbage

#------------------

run_case("call_with_py_ok", """
callWith(Obj('one'), function () {});
""", """
""")

run_case("call_with_py_in_js_from_js_ok", """
function jsCallWith(obj, f) {
f(obj);
}
jsCallWith({x: Obj('one')}, function () {});
""", """
""")

run_case("call_with_py_in_js_from_py_fail", """
callWith({x: Obj('one')}, function () {});
""", """
""")

run_case("failed_workaround", """
var durf = {x: Obj('one')};
callWith(durf, function () {});
""", """
durf = null;
""")

run_case("successful_workaround", """
var durf = {x: Obj('one')};
callWith(durf, function () {});
""", """
durf.x = null;
durf = null;
""")

What is the expected output? What do you see instead?

I expect all 5 cases to have the tracked object deleted. However, the
"call_with_py_in_js_from_py" and "failed_workaround" cases don't free the
tracked object, even though it's no longer reachable.

What version of the product are you using? On what operating system?

PyV8 r443 , Python 2.6.6, Windows 7

Please provide any additional information below.

```

Original issue reported on code.google.com by `csaft...@gmail.com` on 21 Jul 2013 at 9:34

Attachments:
- [pyv8-bug-193.py](https://storage.googleapis.com/google-code-attachments/pyv8/issue-193/comment-0/pyv8-bug-193.py)