Crash when accessing python data via JavaScript

```
Forgive me for not creating a minimal example of the problem yet. Here's a
rough explanation.

I'm creating dicts in Python and then pushing the dicts into a JavaScript
array. Something like this:

data = [];
for (n = 0; n < itemlen; n++) {
item = pyfunc(n);
data.push(item);
}

Later on I return data back to python by calling JSON.stringify(data)

In recent builds, on Mac OS (I haven't tested Windows), PyV8 crashes with a
segmentation fault. Interestingly, when I loop through data, passing each item
back to Python, the crash doesn't happen.

Please let me know what I can do to help resolve this problem.

Here's the relevant part of the crash info:

Process: Python [54082]
Path:
/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/
MacOS/Python
Identifier: org.python.python
Version: 2.7.4 (2.7.4)
Code Type: X86-64 (Native)
Parent Process: bash [62168]
User ID: 501

Date/Time: 2013-05-01 23:56:37.232 -0400
OS Version: Mac OS X 10.8.2 (12C2034)
Report Version: 10

Interval Since Last Report: 285252 sec
Crashes Since Last Report: 28
Per-App Interval Since Last Report: 626 sec
Per-App Crashes Since Last Report: 24
Anonymous UUID: 4E302A2E-F17C-8944-CFBD-D3F305073F4F

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000098

VM Regions Near 0x98:
-->
__TEXT 0000000100000000-0000000100001000 [ 4K] r-x/rwx SM=COW /Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python

Application Specific Information:
Performing @selector(clickedAction:) from sender wxNSMenuItem 0x109753510

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 org.python.python 0x00000001000545c1 dict_dealloc + 33
1 _PyV8.so 0x000000010860993a
ObjectTracer::~ObjectTracer() + 154
2 _PyV8.so 0x0000000108609ba9
ObjectTracer::WeakCallback(v8::Persistent, void*) + 25
3 _PyV8.so 0x000000010872e96d
v8::internal::GlobalHandles::Node::PostGarbageCollectionProcessing(v8::internal:
:Isolate*, v8::internal::GlobalHandles*) + 301
4 _PyV8.so 0x000000010872dd03
v8::internal::GlobalHandles::PostGarbageCollectionProcessing(v8::internal::Garba
geCollector, v8::internal::GCTracer*) + 115
5 _PyV8.so 0x000000010874a289
v8::internal::Heap::PerformGarbageCollection(v8::internal::GarbageCollector,
v8::internal::GCTracer*) + 1817
6 _PyV8.so 0x0000000108749a9c
v8::internal::Heap::CollectGarbage(v8::internal::AllocationSpace,
v8::internal::GarbageCollector, char const*, char const*) + 428
7 _PyV8.so 0x0000000108713443
v8::internal::Factory::NewRawOneByteString(int, v8::internal::PretenureFlag) +
131
8 _PyV8.so 0x000000010888ec79
v8::internal::BasicJsonStringifier::Extend() + 281
9 _PyV8.so 0x000000010888f1de
v8::internal::BasicJsonStringifier::SerializeString(v8::internal::Handle) + 910
10 _PyV8.so 0x00000001088cd48b
v8::internal::BasicJsonStringifier::Result
v8::internal::BasicJsonStringifier::Serialize_(v8::internal::Handle, bool, v8::internal::Handle) + 667
11 _PyV8.so 0x00000001088cce3f
v8::internal::BasicJsonStringifier::Result
v8::internal::BasicJsonStringifier::Serialize_(v8::internal::Handle, bool, v8::internal::Handle) + 3791
12 _PyV8.so 0x00000001088cd9ae
v8::internal::BasicJsonStringifier::Result
v8::internal::BasicJsonStringifier::Serialize_(v8::internal::Handle, bool, v8::internal::Handle) + 1982
13 _PyV8.so 0x00000001088cce3f
v8::internal::BasicJsonStringifier::Result
v8::internal::BasicJsonStringifier::Serialize_(v8::internal::Handle, bool, v8::internal::Handle) + 3791
14 _PyV8.so 0x000000010888e440
v8::internal::BasicJsonStringifier::Stringify(v8::internal::Handle) + 32
15 _PyV8.so 0x00000001088a3431
v8::internal::Runtime_BasicJSONStringify(int, v8::internal::Object**,
v8::internal::Isolate*) + 225
16 ??? 0x0000023b6e80616e 0 + 2454280233326
17 ??? 0x0000023b6e839bfb 0 + 2454280444923
18 ??? 0x0000023b6e80bb14 0 + 2454280256276
19 ??? 0x0000023b6e832e4c 0 + 2454280416844
20 ??? 0x0000023b6e825b64 0 + 2454280362852
21 ??? 0x0000023b6e8077f7 0 + 2454280239095
22 _PyV8.so 0x000000010870a91c
v8::internal::Invoke(bool, v8::internal::Handle,
v8::internal::Handle, int,
v8::internal::Handle*, bool*) + 396
23 _PyV8.so 0x0000000108697e8a v8::Script::Run() + 490
24 _PyV8.so 0x00000001085e256b
CEngine::ExecuteScript(v8::Handle) + 235
25 _PyV8.so 0x00000001085e26e5 CScript::Run() + 53
26 _PyV8.so 0x00000001085d74aa
CContext::EvaluateW(std::basic_string,
std::allocator > const&, std::basic_string, std::allocator >, int, int,
boost::python::api::object) + 250
27 _PyV8.so 0x00000001085df353
boost::python::detail::caller_arity<6u>::impl,
std::allocator > const&, std::basic_string, std::allocator >, int, int,
boost::python::api::object), boost::python::default_call_policies,
boost::mpl::vector7, std::allocator >
const&, std::basic_string,
std::allocator >, int, int, boost::python::api::object>
>::operator()(_object*, _object*) + 1155
28 libboost_python-mt.dylib 0x00000001069d237e
boost::python::objects::function::call(_object*, _object*) const + 766
29 libboost_python-mt.dylib 0x00000001069d447a
boost::detail::function::void_function_ref_invoker0::invoke(boost::detail::function::function_buffer&) + 26
30 libboost_python-mt.dylib 0x00000001069da65c
boost::function0::operator()() const + 28
31 libboost_python-mt.dylib 0x00000001069da37c
boost::python::detail::exception_handler::operator()(boost::function0
const&) const + 28
32 _PyV8.so 0x00000001085cee92
boost::detail::function::function_obj_invoker2, boost::_bi::list3,
boost::arg<2>, boost::_bi::value > >,
bool, boost::python::detail::exception_handler const&, boost::function0
const&>::invoke(boost::detail::function::function_buffer&,
boost::python::detail::exception_handler const&, boost::function0 const&)
+ 34
33 libboost_python-mt.dylib 0x00000001069da578
boost::python::detail::exception_handler::handle(boost::function0 const&)
const + 40
34 libboost_python-mt.dylib 0x00000001069da1cd
boost::python::handle_exception_impl(boost::function0) + 29
35 libboost_python-mt.dylib 0x00000001069d3e83 function_call + 83
36 org.python.python 0x000000010000c9a2 PyObject_Call + 98
37 org.python.python 0x00000001000c0b18 PyEval_EvalFrameEx + 14024
38 org.python.python 0x00000001000c5999 PyEval_EvalCodeEx + 2137
39 org.python.python 0x00000001000c328d PyEval_EvalFrameEx + 24125
40 org.python.python 0x00000001000c5999 PyEval_EvalCodeEx + 2137
41 org.python.python 0x00000001000c328d PyEval_EvalFrameEx + 24125
42 org.python.python 0x00000001000c5999 PyEval_EvalCodeEx + 2137
43 org.python.python 0x000000010003e580 function_call + 176
44 org.python.python 0x000000010000c9a2 PyObject_Call + 98
45 org.python.python 0x000000010001f0bb instancemethod_call + 363
46 org.python.python 0x000000010000c9a2 PyObject_Call + 98
47 org.python.python 0x00000001000bc197
PyEval_CallObjectWithKeywords + 87
48 _core_.so 0x00000001011c88af
wxPyCallback::EventThunker(wxEvent&) + 319
49 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e50b4
wxEvtHandler::ProcessEventIfMatchesId(wxEventTableEntryBase const&,
wxEvtHandler*, wxEvent&) + 84
50 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e619f
wxEvtHandler::SearchDynamicEventTable(wxEvent&) + 111
51 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e72e8
wxEvtHandler::TryHereOnly(wxEvent&) + 40
52 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e74c9
wxEvtHandler::ProcessEvent(wxEvent&) + 265
53 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e51ab
wxEvtHandler::DoTryChain(wxEvent&) + 75
54 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e73aa
wxEvtHandler::ProcessEventLocally(wxEvent&) + 74
55 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e7405
wxEvtHandler::ProcessEvent(wxEvent&) + 69
56 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015e6d76
wxEvtHandler::SafelyProcessEvent(wxEvent&) + 22
57 libwx_osx_cocoau-2.9.5.0.0.dylib 0x0000000101821670
wxWindowBase::HandleWindowEvent(wxEvent&) const + 16
58 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001017ceecb
wxMenuBase::SendEvent(int, int) + 219
59 libwx_osx_cocoau-2.9.5.0.0.dylib 0x000000010164ce41
wxMenu::HandleCommandProcess(wxMenuItem*, wxWindow*) + 97
60 com.apple.AppKit 0x00007fff88f2ea59 -[NSApplication
sendAction:to:from:] + 342
61 com.apple.AppKit 0x00007fff8906444c -[NSMenuItem
_corePerformAction] + 406
62 com.apple.AppKit 0x00007fff8906413a -[NSCarbonMenuImpl
performActionWithHighlightingForItemAtIndex:] + 133
63 com.apple.AppKit 0x00007fff88d5146f -[NSMenu
_internalPerformActionForItemAtIndex:] + 36
64 com.apple.AppKit 0x00007fff88d512f7 -[NSCarbonMenuImpl
_carbonCommandProcessEvent:handlerCallRef:] + 135
65 com.apple.AppKit 0x00007fff8905d245 NSSLMMenuEventHandler +
342
66 com.apple.HIToolbox 0x00007fff85225f0a
DispatchEventToHandlers(EventTargetRec*, OpaqueEventRef*, HandlerCallRec*) +
1206
67 com.apple.HIToolbox 0x00007fff852253d9
SendEventToEventTargetInternal(OpaqueEventRef*, OpaqueEventTargetRef*,
HandlerCallRec*) + 410
68 com.apple.HIToolbox 0x00007fff8523b1bd SendEventToEventTarget +
40
69 com.apple.HIToolbox 0x00007fff85271e89
SendHICommandEvent(unsigned int, HICommand const*, unsigned int, unsigned int,
unsigned char, void const*, OpaqueEventTargetRef*, OpaqueEventTargetRef*,
OpaqueEventRef**) + 443
70 com.apple.HIToolbox 0x00007fff85216c11
SendMenuCommandWithContextAndModifiers + 59
71 com.apple.HIToolbox 0x00007fff85216bc3 SendMenuItemSelectedEvent
+ 254
72 com.apple.HIToolbox 0x00007fff85216a4f
FinishMenuSelection(SelectionData*, MenuResult*, MenuResult*) + 94
73 com.apple.HIToolbox 0x00007fff851f2aab MenuSelectCore(MenuData*,
Point, double, unsigned int, OpaqueMenuRef**, unsigned short*) + 605
74 com.apple.HIToolbox 0x00007fff851f20b8 _HandleMenuSelection2 +
565
75 com.apple.AppKit 0x00007fff88f1c9c6 _NSHandleCarbonMenuEvent
+ 245
76 com.apple.AppKit 0x00007fff88e3eb7f _DPSNextEvent + 2073
77 com.apple.AppKit 0x00007fff88e3ded2 -[NSApplication
nextEventMatchingMask:untilDate:inMode:dequeue:] + 128
78 com.apple.AppKit 0x00007fff88e35283 -[NSApplication run] + 517
79 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001016e0163 wxGUIEventLoop::DoRun()
+ 51
80 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001015b1d07 wxCFEventLoop::Run() +
55
81 libwx_osx_cocoau-2.9.5.0.0.dylib 0x00000001014b0008
wxAppConsoleBase::MainLoop() + 72
82 _core_.so 0x00000001011c372c wxPyApp::MainLoop() + 76
83 _core_.so 0x000000010120fe3f
wxPySizer::wxCreateObject() + 202719
84 org.python.python 0x00000001000c3b12 PyEval_EvalFrameEx + 26306
85 org.python.python 0x00000001000c5999 PyEval_EvalCodeEx + 2137
86 org.python.python 0x000000010003e580 function_call + 176
87 org.python.python 0x000000010000c9a2 PyObject_Call + 98
88 org.python.python 0x000000010001f0bb instancemethod_call + 363
89 org.python.python 0x000000010000c9a2 PyObject_Call + 98
90 org.python.python 0x00000001000c0b18 PyEval_EvalFrameEx + 14024
91 org.python.python 0x00000001000c40bd PyEval_EvalFrameEx + 27757
92 org.python.python 0x00000001000c5999 PyEval_EvalCodeEx + 2137
93 org.python.python 0x00000001000c5ab6 PyEval_EvalCode + 54
94 org.python.python 0x00000001000ea32e PyRun_FileExFlags + 174
95 org.python.python 0x00000001000ea5ca PyRun_SimpleFileExFlags +
458
96 org.python.python 0x000000010010155d Py_Main + 3101
97 org.python.python 0x0000000100000f14 0x100000000 + 3860

```

Original issue reported on code.google.com by `artlo...@gmail.com` on 2 May 2013 at 3:59