Re: Emacs's set-frame-size can not work well with gnome-shell?

[martin rudalics]

> Yes, that works both with Lucid and Motif. BTW, dragging bottom and right 
borders is fast and smooth, but dragging top-left is very choppy.

Because the frame has to resize _and_ move.  GTK has an internal
function that moves and resizes a window in one go but I haven't seen an
external interface to it.

> Unfortunately, I'm getting reports that the Lucid build is much slower
> than GTK at least for some others:

I can't comment on that.  I only have non-optimized Lucid builds here
and they are much too slow to do anything with child frames at all.

Next thing to try: Before the

  gtk_window_get_size (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)),
                       &gwidth, &gheight);

lines in xg_frame_set_char_size insert the two lines

  if (!gtk_window_get_resizable (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f))))
    gtk_window_set_resizable (GTK_WINDOW (FRAME_GTK_OUTER_WIDGET (f)), TRUE);

put a breakpoint on the second one and tell me whether you get a hit.
Just to make sure ...

martin