Subject: bug#20343: csv-mode fails if mode line is customized

From: Peter Eisentraut <[email-masked]>
Date: Wed, 15 Apr 2015 20:00:23 -0400

This is about csv-mode.el version 1.2 from elpa.gnu.org.

If the mode line has been customized in a certain way, calling csv-mode
will fail.

Example:

in ~/emacs.d/init.el

(setq-default mode-line-format '("%e"))

Install csv-mode.el.

Then run

emacs test.csv

This will produce a message like

(wrong-type-argument number-or-marker-p ("%e"))

The reason is that in the definition of csv-mode-line-format, the
arguments of the `last' function are flipped:

(defconst csv-mode-line-format
  ;; See bindings.el for details of `mode-line-format' construction.
  (let* ((ml (copy-sequence (default-value 'mode-line-format)))
         (x (or (memq 'mode-line-position ml) (last 3 ml))))  ;; wrong

(I doubt that messing around with the mode line like that is current
practice, but that might be a separate discussion.)