[Bug-AUCTeX] Minibuffer tab-completion fails after loading AUCTeX

[Mark Dickinson]

I'm having a problem with Emacs 22.0.50.1 and AUCTeX 11.82 running on
OS X 10.3.9.  The usual emacs minibuffer tab-completion seems to fail
on my system after AUCTeX is loaded.  The sequence of events is as
follows:

1. Launch emacs from a Terminal prompt.  At this stage tab-completion
   works as expected; that is, C-x C-f TAB TAB opens a new buffer
   showing the files in the current directory.

1.5 (Optionally) Carry out various non-TeX activities within Emacs.
   C-x C-f TAB TAB continues to work as expected.

2. Load the tex file test.tex (shown below) using C-x C-f test.tex.

3. Now on typing C-x C-f TAB TAB the message `Making completion
   list...' appears, and then nothing happens: after a second or so
   the minibuffer returns to the `Find file: ' prompt.  The *Messages*
   buffer then shows the error:

   run-hooks: Wrong type argument: stringp, #<objfwd to t>

After doing M-x toggle-debug-on-error and trying C-x C-f TAB TAB
again, I get the following *Backtrace*:

Debugger entered--Lisp error: (error "Apparently circular structure
being printed")
  completion-setup-function()
  run-hooks(completion-setup-hook)
  minibuffer-complete()
  call-interactively(minibuffer-complete)
  read-file-name("Find file: " nil "~/" nil)
  find-file-read-args("Find file: " nil)
  call-interactively(find-file)

More details that may or may not be useful:

I'm running a newly installed version of Emacs 22.0.50.1 (from cvs, 29
Dec, via the darwinports command `port install emacs-devel') together
with AUCTeX 11.82, on Mac OS X version 10.3.9.  However, I've been
having the same problem with older CVS versions of both emacs 22
(installed at various times this over the past month) and also with
version 11.55 of AUCTeX.  The problem seems to occur with and without
the carbon variant of emacs.

Single tab completion (C-x C-f TAB) still works fine, and AUCTeX and
preview-latex show no major problems.  In particular, tab-completion
for TeX commands works as expected.  Other double-tab completion in
Emacs (e.g. C-x b TAB TAB, etc.) seems to fail in the same way as
above.

It doesn't seem to matter which TeX file I load.  The file `test.tex'
that I referred to above just contains the following 7 lines:
###test.tex###
\documentclass{article}

\begin{document}

Just testing.

\end{document}
###End test.tex###

Following the suggestion in Appendix C of the AUCTeX manual, I tried
launching emacs with emacs -q -no-site-file and then loading
auctex.el; the problem still occurs.

Any ideas what might be going wrong here?  Please let me know if
I can provide any more information that might be useful.  Any
suggestions as to what I might be doing wrong would be much
appreciated.

Mark

Emacs  : GNU Emacs 22.0.50.1 (powerpc-apple-darwin7.9.0)
 of 2005-12-29 on fibonacci
Package: 11.82

current state:
==============
(setq
 AUCTeX-date "2005-12-17"
 window-system nil
 LaTeX-version "2e"
 TeX-style-path '("style" "auto"
"/opt/local/share/emacs/site-lisp/auctex/style"
"/usr/local/var/auctex")
 TeX-auto-save nil
 TeX-parse-self nil
 TeX-master t
 TeX-command-list '(("TeX" "%(PDF)%(tex) %S%(PDFout) \"%(mode)\\input
%t\"" TeX-run-TeX nil (plain-tex-mode ams-tex-mode texinfo-mode)
                     :help "Run plain TeX")
                    ("LaTeX" "%l \"%(mode)\\input{%t}\"" TeX-run-TeX
nil (latex-mode doctex-mode) :help "Run LaTeX")
                    ("Makeinfo" "makeinfo %t" TeX-run-compile nil
(texinfo-mode) :help "Run Makeinfo with Info output")
                    ("Makeinfo HTML" "makeinfo --html %t"
TeX-run-compile nil (texinfo-mode) :help "Run Makeinfo with HTML
output")
                    ("AmSTeX" "%(PDF)amstex %S%(PDFout)
\"%(mode)\\input %t\"" TeX-run-TeX nil (ams-tex-mode) :help "Run
AMSTeX")
                    ("ConTeXt" "texexec --once --texutil
%(execopts)%t" TeX-run-TeX nil (context-mode) :help "Run ConTeXt
once")
                    ("ConTeXt Full" "texexec %(execopts)%t"
TeX-run-TeX nil (context-mode) :help "Run ConTeXt until completion")
                    ("ConTeXt Clean" "texutil --purgeall"
TeX-run-interactive nil (context-mode) :help "Clean temporary ConTeXt
files")
                    ("BibTeX" "bibtex %s" TeX-run-BibTeX nil t :help
"Run BibTeX")
                    ("View" "dvi2tty -q -w 132 %s" TeX-run-command t t
:help "Run Text viewer")
                    ("Print" "%p" TeX-run-command t t :help "Print the file")
                    ("Queue" "%q" TeX-run-background nil t :help "View
the printer queue" :visible TeX-queue-command)
                    ("File" "%(o?)dvips %d -o %f " TeX-run-command t t
:help "Generate PostScript file")
                    ("Index" "makeindex %s" TeX-run-command nil t
:help "Create index file")
                    ("Check" "lacheck %s" TeX-run-compile nil
(latex-mode) :help "Check LaTeX file for correctness")
                    ("Spell" "<ignored>" TeX-run-ispell-on-document
nil t :help "Spell-check the document")
                    ("Other" "" TeX-run-command t t :help "Run an
arbitrary command"))
 )