bug#18558: 24.4.50; Debugger slow with long strings

[Helmut Eller]

Moving the cursor in the debugger window is very slow in the following
example:

shell> cat test.el
(progn
  (defun foo (n string)
    (cond ((= n 0) (debug))
          (t (foo (1- n) string))))
  (foo 30 (make-string 500000 ?\\)))

shell> emacs -Q -nw -l test.el

Now move the cursor around to see the slowness.

Maybe the debugger should truncate long strings as it does with long
lists.


In GNU Emacs 24.4.50.2 (i686-pc-linux-gnu, GTK+ Version 2.24.10)
 of 2014-09-08 on ix