[Java-gnome-developer] CVS: Problem with gdk_BaseObject.c and GTK_IS_OBJECT()

[Santeri P. <sa...@ik...>]

In CVS version, in other/gdk_BaseObject.c:

jobject makeBaseObjectSubclass (JNIEnv *env, jclass cls, void *peer)
{
  if (peer == NULL)
    return NULL;
  else if (GTK_IS_OBJECT(peer))
    return makeBaseObjectClass(env, peer);
  else {
    jobject result = (*env)->AllocObject (env, cls);
    jlong result_jl;

    *(void **) &result_jl = peer;
    (*env)->SetLongField (env, result, nativepeerFid, result_jl);
    return result;
  }
}

The GTK_IS_OBJECT is a problem, if you try to create any object not based
on Gtk, like GdkGC:

	xx = new GdkGC(yy);

leads to:

Program received signal SIGSEGV, Segmentation fault.
0x41383ed6 in makeBaseObjectSubclass (env=0x400887d4, cls=0x6,
peer=0x81244f8)
    at other/gdk_BaseObject.c:70
70        else if (GTK_IS_OBJECT(peer))

This, of course happens because "peer" in this context is not a Gtk
object, but instead a GdkWindow, which isn't representable in the Gtk
object system:

(gdb) p *(GdkGC*)peer
$14 = {dummy_var = 1701080693}
(gdb) p *((GtkObject*)peer)
$15 = {klass = 0x65646e75, flags = 135415064, ref_count = 135220712,
  object_data = 0x1}
(gdb) p *((GtkObject*)peer)->klass
Cannot access memory at address 0x65646e75

In noticed the GTK_IS_OBJECT was added in version 1.5 (of that file).
Apparently this hasn't been noticed since the test and sample programs
don't use GdkGC directly at all..

--
sa...@ik...                    I have become death, destroyer of the worlds.