Thread 1 "emacs" hit Breakpoint 1, xg_scroll_callback (range=0x2f58750, 
    scroll=GTK_SCROLL_JUMP, value=6164892.9000000004, 
    user_data=0x1493c30 <bss_sbrk_buffer+8990864>) at xterm.c:5644
5644	{
(gdb) next
5648	  GtkAdjustment *adj = GTK_ADJUSTMENT (gtk_range_get_adjustment (range));
(gdb) next
5649	  struct frame *f = g_object_get_data (G_OBJECT (range), XG_FRAME_DATA);
(gdb) print gtk_adjustment_get_upper(adj)
value has been optimized out
(gdb) next
5648	  GtkAdjustment *adj = GTK_ADJUSTMENT (gtk_range_get_adjustment (range));
(gdb) next
5649	  struct frame *f = g_object_get_data (G_OBJECT (range), XG_FRAME_DATA);
(gdb) next
5651	  if (xg_ignore_gtk_scrollbar) return false;
(gdb) print gtk_adjustment_get_upper(adj)
$9 = 49781840
(gdb) print gtk_adjustment_get_page_size(adj)
$10 = 49781840
(gdb) cont
Continuing.