C stack overflow in print_preprocess

[Kalle Olavi Niemitalo]

Start Emacs with --no-init-file --no-site-file.
Evaluate the following expressions in the *scratch* buffer:

(setq print-circle nil
      print-gensym t)
'#1=(#1#)

This causes a segmentation fault.  GDB shows that
print_preprocess has been calling itself thousands of times.
It has apparently been scanning the structure for uninterned
symbols, to satisfy print-gensym; but because print-circle is
nil, it has not bothered checking for recursive conses.  This
goes against the documentation of print-circle, which implies
printing a circular structure could only cause a Lisp error.

In GNU Emacs 21.3.50.31 (i386-pc-linux-gnu, GTK+ Version 2.4.0)
 of 2004-04-23 on Astalo
configured using `configure '--prefix=/home/kalle' 
'--exec-prefix=/home/kalle/i386-pc-linux-gnu' '--host=i386-pc-linux-gnu' 
'--build=i386-pc-linux-gnu' '--enable-maintainer-mode' '--with-x-toolkit=gtk' 
'CFLAGS=-O2 -g -Wall -W' 'CPPFLAGS=-I/home/kalle/include' 
'LDFLAGS=-L/home/kalle/i386-pc-linux-gnu/lib' 'build_alias=i386-pc-linux-gnu' 
'host_alias=i386-pc-linux-gnu''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: fi_FI.UTF-8
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  encoded-kbd-mode: t
  menu-bar-mode: t
  unify-8859-on-encoding-mode: t
  line-number-mode: t

Recent input:
ESC O B ESC x r e p o r t SPC e m TAB RET

Recent messages:
(/home/kalle/i386-pc-linux-gnu/bin/emacs --no-init-file --no-site-file)
Loading encoded-kb...done
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