[Bug:cli] Loading user-defined function generates an internal error

[nickrob at snap dot net dot nz (Nick Roberts)]

If the user-defined function below is put in a file user.cmd, say, then in
internal error is generated upon loading it:

..
(gdb) source user.cmd
utils.c:1206: internal-error: virtual memory exhausted.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) [answered Y; input not from terminal]
utils.c:1206: internal-error: virtual memory exhausted.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Create a core file of GDB? (y or n) [answered Y; input not from terminal]
Aborted (core dumped)

This didn't used to happen, say 3 months ago.

-- 
Nick                                           http://users.snap.net.nz/~nickrob


define p_tree

  set $tree = ($arg0)
  set $i = 0
  set $node = $tree->_M_t->_M_impl->_M_header->_M_left
  set $tree_size = $tree->_M_t->_M_impl->_M_node_count

  while ($i < $tree_size)
    set $i++
    printf "NODE %d: ", $i
    set $value = (void *)($node + 1)
    p *($arg1 *)$value
    set $value = $value + 4
    p *($arg2 *)$value

    # Next (bigger) value must be to right...
    if ($node->_M_right != 0)
      set $node = $node->_M_right

      # Descend tree while there is a left node.
      while ($node->_M_left != 0)
        set $node = $node->_M_left
      end

      # ...or further up the tree.
    else
      set $tmp_node = $node->_M_parent

      # Ascend tree while at right node.
      while ($node == $tmp_node->_M_right)
        set $node = $tmp_node
        set $tmp_node = $tmp_node->_M_parent
      end

      # Set to parent of first left node (condition always true?)
      if ($node->_M_right != $tmp_node)
        set $node = $tmp_node
      end
    end
  end
end