RE: Timer scheduling and cancel-timer

["Drew Adams" <drew.adams@oracle.com>]

I have no idea whether this is relevant, but I'll mention it, as it might be.

I have used Francis Wright's library `dired-sort-menu.el' for years.  Yesterday,
with a build from 2013-01-18, I somehow got in a situation where this kept
happening:

Debugger entered--Lisp error: (wrong-type-argument integer-or-marker-p t)
  #[nil ...
  ad-Advice-show-paren-function(#[nil...
  show-paren-function()
  apply(show-paren-function nil)
  #[nil ... [timer apply 5 6] 4]()
  timer-event-handler([t 0 0 125000 t show-paren-function nil idle 0])

It happened over and over and over: as soon as I quit the debugger it popped up
again.  `dired-sort-menu.el' has this defadvice, which is apparently the one
involved here:

(defadvice show-paren-function (around show-paren-function-advice activate)
  "Do not show matching parens in a dired sort dialogue buffer."
  (or (dired-sort-dialogue-buffer-p (buffer-name)) ad-do-it))

I was able to quit the Emacs session, and I have not seen the problem since,
even with the same build.

Again, dunno whether this is related to your discussion.  Ignore if not.