Crash when clicking on model.

[GoogleCodeExporter]

I'm getting a crashing when clicking on a model with the latest code from the 
repository (2011/03/23).  This is my own build in Ubuntu 10.10 on a 64-bit 
machine.

Here is the stack dump from gdb run postmortem on the core file.

Core was generated by `heekscad'.
Program terminated with signal 11, Segmentation fault.
#0  0x000000000058c36d in MarkedList::ObjectsInWindow (this=0x29165f0, 
window=..., marked_object=0x7fff1f8f5f20, single_picking=true) at 
/opt/HeeksCAD/HeeksCAD/src/MarkedList.cpp:170
170                         if((object->GetType() == GripperType) || ((object->GetMarkingMask() & 
m_filter) && (object->GetMarkingMask() != 0))){
(gdb) bt
#0  0x000000000058c36d in MarkedList::ObjectsInWindow (this=0x29165f0, 
window=..., marked_object=0x7fff1f8f5f20, single_picking=true) at 
/opt/HeeksCAD/HeeksCAD/src/MarkedList.cpp:170
#1  0x000000000058c832 in MarkedList::FindMarkedObject (this=0x29165f0, 
point=..., marked_object=0x7fff1f8f5f20) at 
/opt/HeeksCAD/HeeksCAD/src/MarkedList.cpp:230
#2  0x00000000005a6d89 in CViewport::FindMarkedObject (this=0x2b03280, 
point=..., marked_object=0x7fff1f8f5f20) at 
/opt/HeeksCAD/HeeksCAD/src/GraphicsCanvas.cpp:656
#3  0x0000000000657704 in HeeksCADapp::FindMarkedObject (this=0x2915ce0, 
point=..., marked_object=0x7fff1f8f5f20) at 
/opt/HeeksCAD/HeeksCAD/src/HeeksCAD.cpp:629
#4  0x000000000079924a in CSelectMode::OnMouse (this=0x2916470, event=...) at 
/opt/HeeksCAD/HeeksCAD/src/SelectMode.cpp:124
#5  0x00000000005a5cc2 in CViewport::ViewportOnMouse (this=0x2b03280, 
event=...) at /opt/HeeksCAD/HeeksCAD/src/GraphicsCanvas.cpp:337
#6  0x00000000005a5daf in CGraphicsCanvas::OnMouse (this=0x2b03000, event=...) 
at /opt/HeeksCAD/HeeksCAD/src/GraphicsCanvas.cpp:355
#7  0x00007f4555bf3310 in 
wxEvtHandler::ProcessEventIfMatches(wxEventTableEntryBase const&, 
wxEvtHandler*, wxEvent&) () from /usr/lib/libwx_baseu-2.8.so.0
#8  0x00007f4555bf42d4 in wxEventHashTable::HandleEvent(wxEvent&, 
wxEvtHandler*) () from /usr/lib/libwx_baseu-2.8.so.0
#9  0x00007f4555bf43b7 in wxEvtHandler::ProcessEvent(wxEvent&) () from 
/usr/lib/libwx_baseu-2.8.so.0
#10 0x00007f45556ed652 in ?? () from /usr/lib/libwx_gtk2u_core-2.8.so.0
#11 0x00007f454a1469d8 in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#12 0x00007f4548884a6e in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#13 0x00007f454889ade7 in ?? () from /usr/lib/libgobject-2.0.so.0
#14 0x00007f454889c0eb in g_signal_emit_valist () from 
/usr/lib/libgobject-2.0.so.0
#15 0x00007f454889c863 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#16 0x00007f454a25f6df in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#17 0x00007f454a13ee73 in gtk_propagate_event () from 
/usr/lib/libgtk-x11-2.0.so.0
#18 0x00007f454a13ff4b in gtk_main_do_event () from /usr/lib/libgtk-x11-2.0.so.0
#19 0x00007f4549db974c in ?? () from /usr/lib/libgdk-x11-2.0.so.0
#20 0x00007f4547fc3342 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#21 0x00007f4547fc72a8 in ?? () from /lib/libglib-2.0.so.0
#22 0x00007f4547fc77b5 in g_main_loop_run () from /lib/libglib-2.0.so.0
---Type <return> to continue, or q <return> to quit---
#23 0x00007f454a1403e7 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
#24 0x00007f45556da578 in wxEventLoop::Run() () from 
/usr/lib/libwx_gtk2u_core-2.8.so.0
#25 0x00007f455575fb1b in wxAppBase::MainLoop() () from 
/usr/lib/libwx_gtk2u_core-2.8.so.0
#26 0x000000000066a7ed in HeeksCADapp::OnRun (this=0x2915ce0) at 
/opt/HeeksCAD/HeeksCAD/src/HeeksCAD.cpp:3315
#27 0x00007f4555b99695 in wxEntry(int&, wchar_t**) () from 
/usr/lib/libwx_baseu-2.8.so.0
#28 0x000000000064f11d in main (argc=1, argv=0x7fff1f8f6ef8) at 
/opt/HeeksCAD/HeeksCAD/src/HeeksCAD.cpp:74

Original issue reported on code.google.com by jcoffl...@gmail.com on 23 Mar 2011 at 11:54

[GoogleCodeExporter]

Looks like a null pointer dereference to me.

Original comment by jcoffl...@gmail.com on 23 Mar 2011 at 11:55

[GoogleCodeExporter]

This is a problem with 64bit computers. ( I don't have a 64 bit computer ).
The problem is that I am using a cast memory point of my HeeksObj objects, as a 
"name" for the OpenGL picking.
See this line in HeeksCAD/src/MarkedList.cpp:
HeeksObj *object = (HeeksObj *)(data[pos]);

The problem is that the "name" data, that it is casting back from, is probably 
only 32-bit, so we are getting a bad memory pointer.

or maybe it's a problem that I am casting using "unsigned long" and that is 
messing up the 64-bit pointer.
( see this code in src/HeeksCAD.cpp :
if(select)glPushName((unsigned long)object)

Original comment by danhe...@gmail.com on 23 Mar 2011 at 12:04