outline-mode

[Sean Sieger]

On GNU Emacs 23.0.0.3 (i686-pc-linux-gnu, GTK+ Version 2.10.11) of
2007-09-22 on 6dfpj71, I have been visiting my outline files using `C-x
r b'; `C-x C-f'; and `C-x d' and finding the fontification erroneous.
That is, the top level, instead of blue is pink (I haven't altered the
defaults) and when I do `C-c C-q' on them, I get,

Debugger entered--Lisp error: (error "Must keep at least one level of headers")
  signal(error ("Must keep at least one level of headers"))
  error("Must keep at least one level of headers")
  hide-sublevels(0)
  call-interactively(hide-sublevels)

...it wasn't until today that in the midst of properly fontified top
level headings there was a single improperly fontified one, so that
there is also an irregularity to the error.

I hope this is helpful.