Re: utf8 char display in buffer

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 13 Jun 2009 08:30:37 -0400
> From: ken <gebser@mousecar.com>
> Reply-To:  gebser@mousecar.com
> 
> ^[$-1 ¡ is 'a' with a horizontal bar over it.  On first inputting it
> (after doing "set-input-method latin-4-postfix" and before changing the
> input method to anything else), it appears correctly and "C-u C-x =" yields:
> 
> =============================================
> 
>   character: ^[$-1 ¡ (05140, 2656, 0xa60)
>     charset: latin-iso8859-4
> 	     (Right-Hand Part of Latin Alphabet 4 (ISO/IEC 8859-4): ISO-IR-110)
>  code point: 96
>      syntax: word
>    category: l:Latin
> buffer code: 0x84 0xE0
>   file code: 0xC4 0x81 (encoded by coding system mule-utf-8-unix)
>        font: -ETL-Fixed-Medium-R-Normal--16-160-72-72-C-80-ISO8859-4
> 
> =============================================
> 
> When I reload the file (revisit the file), the same character is
> replaced with a little box.  Doing "C-u C-x =" here yields:
> 
> =============================================
> 
>   character: ^[$-1 ¡ (01210041, 331809, 0x51021)
>     charset: mule-unicode-0100-24ff
> 	     (Unicode characters of the range U+0100..U+24FF.)
>  code point: 32 33
>      syntax: word
>    category: l:Latin
> buffer code: 0x9C 0xF4 0xA0 0xA1
>   file code: 0xC4 0x81 (encoded by coding system mule-utf-8-unix)
>        font: -- none --
> 
> =============================================

So I think everything is clear now: you have a font that covers this
characters when they are from the 8859-4 character set, but you do not
have a font that covers them in Unicode.  You should install the
Unicode font that supports these characters.

> As for the meaning of the two outputs above, all that I can confidently
> glean is that, if I want to use non-English characters in emacs, I have
> to be an expert emacs developer.  :)

That's exaggeration, I think.  You can use the "C-u C-x =" command,
just as you did above, to find out what Emacs thinks about each
character that is displayed as an empty box.  You can then look for
fonts that cover these characters.  "C-u C-x =" is a user-level
command, and one of its uses is precisely this: to find out what fonts
are missing on your machine.