Re: [Reiter.Joachim@web.de: Failure to show "German Umlaute"]

[Jason Rumney <jasonr@gnu.org>]

Reiner Steib wrote:
> Yes.  E.g. in <http://www.hobbyecke-pc.de/images/screensh2.png> the
> text says:
>
> ,----
> |   wä wö mä mö
> | 
> | In the letters "w" and "m", the right column of pixels is not
> | displayed.
> | 
> |   wa wo ma mo
> `----
>
> If the iso-characters "ä" and "ö" are replaced by their ASCII
> "counterparts" ("a" and "o") the letters "w" and "m" are displayed
> correctly.
>   

The simple explanation for that is that Emacs displays runs of
characters from the same character set using one system call. But since
Emacs considers latin-1 and ascii as different character sets, in the
former case, each character is displayed individually, so clipping
occurs per character rather than on the whole string. In the latter
case, you will see the same problem if you move the cursor through the
text, as that will cause the character under the cursor to be drawn
individually.

Courier New is particularly bad for exhibiting this problem.
Unfortunately it is also one of the few fixed width fonts we can rely on
being installed on all Windows installations, so it is the default.