GdkPixbuf leaks memory

[Dov Grobgeld <dov Orbotech COM>]

Hello,

I have during the last couple of days been hunting for a memory leak
connected to GdkPixbuf. It turns out that the perl bindings of a
GdkPixbuf never frees up the Pixbuf. It has something to do with the
reference counting of the Pixbuf, though I don't fully understand how.

To check this I added the following ugly xs function to GdkPixbuf.

    int
    gdk_pixbuf_get_refcount (pixbuf)
            Gtk::Gdk::Pixbuf    pixbuf
            CODE:
            RETVAL = *(int*)pixbuf;
            OUTPUT:
            RETVAL

(By inspecting the private section of the GdkPixbuf, I found that the
reference count is the first integer in the private section.)

Now if I in a perl program do the following:

    $pb = new_from_file Gtk::Gdk::Pixbuf($file);
    print "Refcount = ", $pb->get_refcount(),"\n";

The answer I get is:

    Refcount = 2
    
In the DESTROY function that may be found in the GdkPixbuf.c after the
conversion from xs, there is only one call to gdk_pixbuf_unref(). 
Since memory is only freed up when the reference count goes to zero,
the memory is never freed up.

But I must admit I don't understand why the refcount got increased to
2. There are no further calls to gdk_pixbuf_ref() in the C-code. And
I also don't understand why I have to call DESTROY manually? Shouldn't
it be called manually when the perl variable is undef'd?

In the end I made a work around by manully adding another
gdk_pixbuf_unref() in the C-code. But that is obviously not the way to
do it...

Does someone with more experience with xs-code and gtk have any idea
of what is going on??

Btw, all these tests were done on Gtk-Perl-0.7006 from CPAN.

Regards,
Dov
--
               Disclaimer: All views above are mine alone.