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[themusicgod1 <508618@xxxxxxxxxxxxxxxxxx>]

** Also affects: emacs24 (Ubuntu)
   Importance: Undecided
       Status: New

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https://bugs.launchpad.net/bugs/508618

Title:
  Setting max-specpdl-size of 34295 allows segfaults with 'simple' elisp

Status in emacs23 package in Ubuntu:
  New
Status in emacs24 package in Ubuntu:
  New

Bug description:
  Binary package hint: emacs23

  Setting max-specpdl-size higher than 34295, and then running the following code results in a segfault of emacs.  I am 
  running a system of mostly 9.04 with some packages (such as this one) upgraded. I know it's kind of pushing emacs to the limit, but still;  this seems like an arbitrary limit on emacs' otherwise diety-like functionality.  What should happen is emacs should continue to fail to execute with "file-truename: Variable binding depth exceeds max-specpdl-size"  as it does below 34295., or at the very least when setting max-specpdl-size higher than 34295 it should warn you that you are making some kind of error if this is not acceptable.

  example code:

  (defun por (pcurrent pb numberleft)
         (if (= numberleft 0)
         	   pcurrent
  	   (por (- (+ pcurrent pb) (* pcurrent pb)) pb (- numberleft 1))))

  (por 0 0.01 10000)

  (setq max-lisp-eval-depth 1000000)  ; this may be necessary, but doesn't appear to be the problem
  (setq max-specpdl-size 34295)          ; setting this lower results in predictable, expected behaviour - emacs refuses to run the result, citing max-specpdl-size not high enough.   Setting this higher (like...34296), results in a segfault of emacs

  emacs23:
    Installé : 23.1+1-4ubuntu3
    Candidat : 23.1+1-4ubuntu3
   Table de version :
   *** 23.1+1-4ubuntu3 0
          100 /var/lib/dpkg/status

  ProblemType: Bug
  Architecture: amd64
  DistroRelease: Ubuntu 9.04
  Package: emacs23 23.1+1-4ubuntu3
  ProcEnviron:
   PATH=(custom, user)
   LANG=fr_CA.UTF-8
   SHELL=/bin/bash
  SourcePackage: emacs23
  Uname: Linux 2.6.28-16-generic x86_64
  UnreportableReason: Ceci n'est pas un authentique paquet Ubuntu

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