[Help-smalltalk] GNU Smalltalk crashes when calling xcb_create_window via cCall

[Dmitry Matveev]

Hello everybody!

It's me with my incomplete-xcb-binding again...

To create a window with XCB, I have to call the xcb_create_window()
function. It has the following prototype:

xcb_void_cookie_t
xcb_create_window (xcb_connection_t *c,
                   uint8_t           depth,
                   xcb_window_t      wid,
                   xcb_window_t      parent,
                   int16_t           x,
                   int16_t           y,
                   uint16_t          width,
                   uint16_t          height,
                   uint16_t          border_width,
                   uint16_t          _class,
                   xcb_visualid_t    visual,
                   uint32_t          value_mask,
                   const uint32_t   *value_list);

I wrote the following Smalltalk code to call this function:
Xcb class >> createWindow: aConnection depth: aDepth windowId: wID
    parent: parentID x: posX y: poxY width: aWidth height: aHeight
    borderWidth: bWidth class: aClass visual: aVisual valueMask: aMask
    valueList: aList [
        <cCall: 'xcb_create_window' returning: #void args:
            #(#cObject #char #uInt #uInt #short #short #ushort #ushort
#ushort #ushort #uInt #uInt #cObject)>
    ]
(Yes, its ugly)

When I execute it, I get
`--> gst -f xcbroot.st
xcbroot.st:94: Aborted
xcbroot.st:94: Error occurred while not in byte code interpreter!!
/lib/i686/cmov/libc.so.6(abort+0x188)[0xb7cd3d68]
/usr/local/bin/../lib/libgst.so.7[0xb7e76d19]
zsh: abort      gst -f xcbroot.st

If I will write simple wrapper in my library like...

void
gst_xcb_create_window
    (...the same arguments as for xcb_create_window...)
{
    xcb_create_window (...the arguments...);
}

...and if I will use it instead of "native" xcb functions, e.g.

    <cCall: 'gst_xcb_create_window' ...>

everything will work fine. I've found that only two xcb functions need
such wrappers: xcb_create_window and xcb_map_window.

Is it a GNU Smalltalk bug? Why calls to my own library with the same
functions work? Or I have buggy xcb that is can not be bound... All I
want is just to make this world a bit better :)

With best regards,
Dmitry Matveev

P.S. Attachments:
 * gst-crash-gdb.txt - the GDB output (run & bt) when GST crashes
(direct calls to xcb functions). I hope it will be useful
 * xcbroot.st - the "binding"
 * xcb-gst.c - the wrappers

P.P.S `--> uname -a
Linux debian 2.6.26-2-686 #1 SMP Sun Jun 21 04:57:38 UTC 2009 i686 GNU/Linux

gst-crash-gdb.txt
Description: Text document

xcbroot.st
Description: Binary data

xcb-gst.c
Description: Text Data