[PD] Trying to track a ghost pdtk_canvas_getscroll call

[Ivica Ico Bukvic]

Hi all,

I have a real pickle in trying to debug Pd. Namely, when I grep-ed every
single instance of pdtk_canvas_getscroll and commented it out, it still
gets invoked somehow and I am at a loss how. I know it occurs as many
times as there are objects selected that have been moved (so it is
definitely per-object) 

The only thing I managed to isolate so far is the following code:
g_editor.c

void gobj_displace(t_gobj *x, t_glist *glist, int dx, int dy)
{
    if (x->g_pd->c_wb && x->g_pd->c_wb->w_displacefn)
        (*x->g_pd->c_wb->w_displacefn)(x, glist, dx, dy);
}

I am however unable to decipher what function is exactly being called by
(*x->g_pd->c_wb->w_displacefn). I only found in g_canvas.h definition of
w_displacefn as part of _widgetbehavior struct but nowhere (except in
iemgui objects) is it linked to anything I can actually understand.
Where does this struct get initialized?

Any help on this one would be most appreciated as that will put a stop
on me pulling my hairs out :-)

Best wishes,

Ico