Re: [Stephen.Berman@bogus.example.com: Emacs hangs while edebugging recentf.el]

[Chong Yidong <cyd@stupidchicken.com>]

martin rudalics <rudalics@gmx.at> writes:

>  > It works for me, at least using the recipe given in the original
>  > email.  What steps are you using?
>
> `edebug-defun' on `widget-field-find' and customizing some arbitrary
> editable field.  And `edebug-print-level' equalling 50.  My (Windows ME)
> swap area quickly grew from its usual 70MB to nearly 500MB before I was
> able to kill Emacs.

OK, I guess that hack was not good enough to cover all situations.
Try this one; it should be pretty much bulletproof.


*** emacs/src/print.c.~1.215.~	2005-12-15 19:09:36.000000000 -0500
--- emacs/src/print.c	2005-12-16 10:20:17.000000000 -0500
***************
*** 1313,1326 ****
  
    /* Give up if we go so deep that print_object will get an error.  */
    /* See similar code in print_object.  */
!   /* Because print_preprocess "follows" nested lists in a slightly
!      different order from print_object, there is a risk of giving up
!      too soon.  In that case, a deeply nested circular list may cause
!      print_object to loop.  Using 3 * PRINT_CIRCLE should make this
!      possibility negligible, but at some point someone will have to
!      sit down and do a more careful analysis. -- cyd */
!   if (print_depth >= 3 * PRINT_CIRCLE)
!     return;
  
    /* Avoid infinite recursion for circular nested structure
       in the case where Vprint_circle is nil.  */
--- 1313,1320 ----
  
    /* Give up if we go so deep that print_object will get an error.  */
    /* See similar code in print_object.  */
!   if (print_depth >= PRINT_CIRCLE)
!     error ("Apparently circular structure being printed");
  
    /* Avoid infinite recursion for circular nested structure
       in the case where Vprint_circle is nil.  */
*** emacs/lisp/emacs-lisp/edebug.el.~3.84.~	2005-12-13 21:38:03.000000000 -0500
--- emacs/lisp/emacs-lisp/edebug.el	2005-12-16 10:29:59.000000000 -0500
***************
*** 3711,3717 ****
  	(print-level (or edebug-print-level print-level))
  	(print-circle (or edebug-print-circle print-circle))
  	(print-readably nil)) ;; lemacs uses this.
!     (edebug-prin1-to-string value)))
  
  (defun edebug-compute-previous-result (edebug-previous-value)
    (if edebug-unwrap-results
--- 3711,3719 ----
  	(print-level (or edebug-print-level print-level))
  	(print-circle (or edebug-print-circle print-circle))
  	(print-readably nil)) ;; lemacs uses this.
!     (condition-case nil
! 	(edebug-prin1-to-string value)
!       (error "# Circular or too deeply-nested structure #"))))
  
  (defun edebug-compute-previous-result (edebug-previous-value)
    (if edebug-unwrap-results