On Tue, Sep 25, 2001 at 09:28:39AM -0400, Dale Scheetz wrote:
> On the installation in question the Xservers file has everything commented
> out. The default-display-manager file contains the line:
>
> /usr/bin/X11/wdm
>
> I put the correct line into the Xservers file and wdm comes up as
> expected! Thanks! (what process should have put this in?)
High-priority debconf questions from gdm, kdm, wdm, and xdm.
> Now I seem to have some font problems. Netscape seems to be OK, but the
> GIMP comes up with [] [] [] [] [] in place of the hint text. The title
> bars are OK but any "filled in" text is just [] repeated. Any hints?
Debian X Window System Frequently Asked Questions (FAQ) List
[...]
*) I recently upgraded some packages, and now instead of readable text, some
characters appear as little gray boxes. Why?
A long-standing bug in many X clients and the widget libraries they use was
recently brought to light by the addition of fonts encoded in ISO 10646-1
("Unicode" in common parlance) to the X Window System. The details are highly
technical.
The short answer: It's a bug in the application, or the widget toolkit (e.g.,
GTK+) that it uses. The authors and maintainers of all commonly-used widget
libraries are aware of the problem and a fix will likely appear in the future
(or may already be available by the time you read this).
It is not -- repeat *NOT* -- a bug in the X server, the X libraries, the X
fonts, or anything having to do with the XFree86 packages.
The long answer, courtesy of Markus Kuhn:
(from <http://www.xfree86.org/pipermail/fonts/2001-March/000569.html>)
ANNOUNCEMENT AND WARNING:
The classic and widely used X11 BDF bitmap font families "-misc-fixed-*",
"-adobe-*", and "-b&h-*" have been extended from ISO8859-1 to ISO10646-1
(Unicode) to accommodate users of more languages and mathematical symbols
under X11 and to facilitate the migration towards UTF-8. They are available
on
http://www.cl.cam.ac.uk/~mgk25/ucs-fonts.html
http://www.cl.cam.ac.uk/~mgk25/download/ucs-fonts-75dpi100dpi.tar.gz
Most likely, XFree86 4.1 will include these "*-iso10646-1" fonts, so they
will become quickly widely installed.
Unfortunately, GTK+ 1.2.3 contained a bug that was triggered by the mere
presence of a certain Unicode font, namely
-Adobe-Helvetica-Medium-R-Normal--12-120-75-75-P-67-ISO10646-1
In gtk/gtkstyle.c, the line
gdk_font_load ("-adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*");
simply picks the first font in the alphabet that matches the wildcard. With
the ISO10646-1 fonts present, this will be
-Adobe-Helvetica-Medium-R-Normal--12-120-75-75-P-67-ISO10646-1
instead of
-Adobe-Helvetica-Medium-R-Normal--12-120-75-75-P-67-ISO8859-1
Getting an ISO10646-1 font instead of an ISO8859-1 font should normally not
make a big difference to an application. The latter is just a superset of
the former, it contains in the first 256 glyph positions the same Latin-1
characters as the old ISO8859-1 font and just consumes a bit more memory.
Almost all X clients survive the addition of an ISO10646-1 font or even the
replacement of all ISO8859-1 fonts by ISO10646-1 fonts without any problem.
GTK+ 1.2.3 broke badly, because gdk/gdkfont.c contained several unfortunate
code pieces that tested whether a font contained any characters > 0xff and
then treated any string written out in such a font as a (Japanese, etc.) EUC
coded string of 16-bit values. So if you tried to print 8-bit text with an
ISO10646-1 font, all you saw were default character boxes. For this reason,
XFree86 delayed the introduction of ISO10646-1 versions of the Adobe fonts
by a year after I reported this GTK+ bug in 1999-08-06 to gtk-bugs@gimp.org.
This year is soon over.
Newer versions of GTK+ (I just looked at 1.2.9) fixed this problem by
explicitly specifying "*-iso8859-1" in the default font. So I hope nothing
too bad will happen if XFree86 4.1 adds the new fonts soon. However there
might still be numerous older GTK+ applications around for which an update
or workaround will be necessary.
You hereby have been warned!
Other clients and toolkits have similar issues anytime they request a font
with no specific character set or encoding in the request, but make
assumptions about the properties of the font they get back (for instance, that
it contains no more than 256 codepoints). The moral? Don't claim to not care
about such things as character set encodings if you actually do care. If you
want ISO 8859-1, ask for it.
--
G. Branden Robinson | Suffer before God and ye shall be
Debian GNU/Linux | redeemed. God loves us, so He
branden@debian.org | makes us suffer Christianity.
http://people.debian.org/~branden/ | -- Aaron Dunsmore
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