Subject: Re: bug#12054: 24.1; regression? font-lock no-break-space with nil nobreak-char-display

From: Stefan Monnier <[email-masked]>
Date: Sat, 03 Nov 2012 16:36:42 -0400

> OK, so then do you think this should DTRT?
> (font-lock-add-keywords nil '(("\\(\302\240\\)+" (0 'foo t))) 'APPEND)

That will match if your buffer contains a \302 byte or a \240 byte.
"contains" is different from "is represented internally".

The internal representation should normally stay hidden and only appear
if you use dangerous things like string-as-multibyte or call
set-buffer-multibyte in a non-empty buffer.

> I'm guessing it shouldn't, because IIUC the buffer in fact contains only the
> single raw byte \240 and not the multibyte sequence of two raw bytes \302 and
> \240.

AFAIK your buffer contains none of that.  It contains a NBSP character,
which is not a byte.

        Stefan