Subject: Re: bug#1164: 23.0.60; Doc strings of mode-name, mode-line-format and format-mode-line

From: Eli Zaretskii <[email-masked]>
Date: Tue, 14 Oct 2008 21:55:50 +0200

> From: Glenn Morris <[email-masked]>
> Cc: [email-masked]
> Date: Tue, 14 Oct 2008 15:42:09 -0400
> 
>       Use `(format-mode-line mode-name)' to ensure a string value.

Many users of format-mode-line do this:

     (format-mode-line mode-name nil nil buf)

where BUF is some buffer.  So evidently this isn't the whole story.