bug#15339: 24.3.50; Control characters are displayed as square in describe-char

[Eli Zaretskii]

> Date: Thu, 12 Sep 2013 16:42:20 +0800
> From: Xue Fuqiao <xfq.free@gmail.com>
> Cc: "15339@debbugs.gnu.org" <15339@debbugs.gnu.org>
> 
> I mean the ‘decomposition’ character property (see the OP).

That portion of the display shows (in this case, since there's no
decomposition) how the raw character in question would be displayed.
And since no available font has a glyph for ^L, you see an empty
square.  That looks correct to me.  You expected to see ^L, but that
comes from a display table, which is bypassed in this case, and for
good reason, as explained above.

So I don't think this is a bug, just something that might not be
expected.

> I tried it, but I can't see even a square.  It is like this:
> 
>   decomposition: (12) ('')

That's not what I see, I see the TTY graphics for Form Feed (FF)
character, which is also correct.  This is on MS-Windows, where the
console font has a glyph for FF, which looks like ♀.