hangs when reading DTD

[Eric Hanchrow]

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

Copy the attached file to /tmp/tiny.dtd         (this DTD isn't tiny at all;
that name was poorly chosen :-)

Start emacs like this:

$ cd ... emacs/src
$ gdb emacs
(gdb) run -Q --funcall=toggle-debug-on-quit /tmp/tiny.dtd

Now just sit an wait ... for a while :- Emacs appears to freeze.  Hit
C-g, and you'll see a stack trace like this:

Debugger entered--Lisp error: (quit)
  looking-at("\\(?:<\\?xml\\s +[^>]*>\\)?\\s
*<\\(?:!--\\(?:.\\|\n\\)*?-->\\s *<\\)*\\(?:!DOCTYPE\\s +[^>]*>\\s *<\\)?\\s
*\\(?:!--\\(?:.\\|\n\\\)*?-->\\s *<\\)*[Hh][Tt][Mm][Ll]")
  #[(re dummy) "\301^H!\207" [re looking-at] 2]("\\(?:<\\?xml\\s
+[^>]*>\\)?\\s *<\\(?:!--\\(?:.\\|\n\\)*?-->\\s *<\\)*\\(?:!DOCTYPE\\s
+[^>]*>\\\s *<\\)?\\s *\\(?:!--\\(?:.\\|\n\\)*?-->\\s
*<\\)*[Hh][Tt][Mm][Ll]" nil)
  assoc-default(nil (("\\(?:<\\?xml\\s +[^>]*>\\)?\\s
*<\\(?:!--\\(?:.\\|\n\\)*?-->\\s *<\\)*\\(?:!DOCTYPE\\s +[^>]*>\\s *<\\)?\\s
*\\(?:!--\\(?\:.\\|\n\\)*?-->\\s *<\\)*[Hh][Tt][Mm][Ll]" . html-mode)
("<\\?xml " . xml-mode) ("\\s *<\\(?:!--\\(?:.\\|\n\\)*?-->\\s
*<\\)*!DOCTYPE " . sgml-m\ode) ("%![^V]" . ps-mode) ("# xmcd " .
conf-unix-mode)) #[(re dummy) "\301^H!\207" [re looking-at] 2])
  set-auto-mode()
  normal-mode(t)
  after-find-file(nil t)
  find-file-noselect-1(#<buffer tiny.dtd> "/tmp/tiny.dtd" nil nil
"/tmp/tiny.dtd" (819246 769))
  find-file-noselect("/tmp/tiny.dtd" nil nil nil)
  find-file("/tmp/tiny.dtd")
  command-line-1(("--funcall=toggle-debug-on-quit" "/tmp/tiny.dtd"))
  command-line()
  normal-top-level()


In GNU Emacs 21.3.50.1 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2004-11-10 on rusty

tiny.dtd
Description: Binary data