Subject: bug#11333: Whitespace mode says it's enabled, when it's really not

From: Kelly Dean <[email-masked]>
Date: Tue, 24 Apr 2012 13:01:57 -0700 (PDT)

I'm using Emacs on X on Debian 6 Stable. emacs-version says GNU Emacs 23.2.1 (i486-pc-linux-gnu, GTK+ Version 2.20.0) of 2010-12-11 on raven, modified by Debian.
Steps to reproduce the bug:
Put in your init file just (global-whitespace-mode 1). Start Emacs.
Switch to the scratch buffer. The modeline says "Lisp Interaction WS". Type some whitespace which whitespace mode would highlight. Notice that it isn't highlighted. Do M-x global-whitespace-mode twice, to toggle it off and back on. Notice that the whitespace is now highlighted.
Make a new buffer. In the modeline it says "Fundamental WS". Type some whitespace. Same problem.
I'm told that in fundamental mode, Emacs intentionally doesn't enable global minor modes, because doing so would break things, which explains why it's initially disabled in your new buffer (though it doesn't explain why it's disabled in the scratch buffer, which isn't in fundamental mode). But if whitespace mode isn't enabled for a particular buffer, then putting "WS" in the modeline for that buffer is deceptive. It shouldn't do it.