bug#1215: 23.0.60; unibyte->multibyte conversion problem (in search-forward and friends)

[Stefan Monnier]

> Let me refer to strings like "<<tag>>" - where the "<<" and ">>" stand
> for guillemets, i.e., the characters that we type with `C-x 8 <' and
> `C-x 8 >' - as "anchors". So: if I produce an anchor string in a
> unibyte buffer and then I search for an occurrence of that string in
> multibyte buffer, the search fails.

There are no guillemets in unibyte buffers.

> ;;--------snip,snip--------
> ;; -*- coding: raw-text-unix -*-
> ;; (save-this-block-as "/tmp/1.txt")
> (progn
>   (find-file "/tmp/2.txt")
>   (goto-char (point-min))
>   (setq anchorstr "«foo»")
>   (message (if (multibyte-string-p anchorstr) "multi" "uni"))
>   (search-forward anchorstr))

There's a bug here, indeed: Emacs should refuse to save such a file,
because raw-text-unix (to which I prefer to refer as `binary') cannot
encode « and ».


        Stefan