decode-coding-region returns octal escapes

decode-coding-region returns octal escapes

[Eli Zaretskii]

To reproduce:

  emacs -Q
  M-x find-file-literally RET etc/tutorials/TUTORIAL.de RET

(The German tutorial is just an example, you can use any one, but
others might need different values of the 3rd argument to
decode-coding-region below.)

Now mark a region that includes non-ASCII characters, for example,
this one, on line 7 of the file:

    da\337 die CONTROL-Taste gedr\374ckt sein mu\337

and type

    M-: (decode-coding-region (mark) (point) 'latin-1 t) RET

The result is that the echo area shows this:

    #("da\337 die CONTROL-Taste gedr\374ckt sein mu\337" 0 39 (charset iso-8859-1))

and the *Messages* buffer shows this:

    #("da\303\237 die CONTROL-Taste gedr\303\274ckt sein mu\303\237" 0 39 (charset iso-8859-1))

But I expected to see this in both cases:

    #("daß die CONTROL-Taste gedrückt sein muß" 0 39 (charset iso-8859-1))

Is this a bug?  If not, what is the explanation for what I see?  Why
are raw bytes inserted instead of decoded characters?

Re: decode-coding-region returns octal escapes

[Kenichi Handa]

In article <uab8ytq12.fsf@gnu.org>, Eli Zaretskii <eliz@gnu.org> writes:

> To reproduce:
>   emacs -Q
>   M-x find-file-literally RET etc/tutorials/TUTORIAL.de RET

> (The German tutorial is just an example, you can use any one, but
> others might need different values of the 3rd argument to
> decode-coding-region below.)

> Now mark a region that includes non-ASCII characters, for example,
> this one, on line 7 of the file:

>     da\337 die CONTROL-Taste gedr\374ckt sein mu\337

> and type

>     M-: (decode-coding-region (mark) (point) 'latin-1 t) RET

> The result is that the echo area shows this:

>     #("da\337 die CONTROL-Taste gedr\374ckt sein mu\337" 0 39 (charset iso-8859-1))

> and the *Messages* buffer shows this:

>     #("da\303\237 die CONTROL-Taste gedr\303\274ckt sein mu\303\237" 0 39 (charset iso-8859-1))

> But I expected to see this in both cases:

>     #("daß die CONTROL-Taste gedrückt sein muß" 0 39 (charset iso-8859-1))

At least decode-coding-string is working correctly.  Please
try this instead:
    M-: (setq str (decode-coding-region (mark) (point) 'latin-1 t)) RET
    C-h v str RET
You'll see the correct multibyte string.

> Is this a bug?  If not, what is the explanation for what I see?  Why
> are raw bytes inserted instead of decoded characters?

It seems that `message' function somehow uses
enable-multibyte-characters of the current buffer to decide
how to show a string.

When I do this after the above C-h v:
    M-: (message "%s" str) RET
I see those octals, but when I do that while I'm in a
multibyte buffer,  I see correct characters.

---
Kenichi Handa
handa@m17n.org