From b1446261ab54d6e3d7d76d5ae4367b295efb7d09 Mon Sep 17 00:00:00 2001 From: Chong Yidong Date: Sat, 25 Oct 2008 17:19:12 +0000 Subject: [PATCH] Document monospace font problems. --- etc/PROBLEMS | 75 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 44 insertions(+), 31 deletions(-) diff --git a/etc/PROBLEMS b/etc/PROBLEMS index ff25ad2a6cd..cae4f3b956c 100644 --- a/etc/PROBLEMS +++ b/etc/PROBLEMS @@ -731,15 +731,31 @@ in Emacs, and then try spell-checking again. * Runtime problems related to font handling -** Under X11, some characters appear as hollow boxes. +** Characters are displayed as empty boxes or with wrong font under X. + +*** This can occur when two different versions of FontConfig are used. +For example, XFree86 4.3.0 has one version and Gnome usually comes +with a newer version. Emacs compiled with Gtk+ will then use the +newer version. In most cases the problem can be temporarily fixed by +stopping the application that has the error (it can be Emacs or any +other application), removing ~/.fonts.cache-1, and then start the +application again. If removing ~/.fonts.cache-1 and restarting +doesn't help, the application with problem must be recompiled with the +same version of FontConfig as the rest of the system uses. For KDE, +it is sufficient to recompile Qt. + +*** Some fonts have a missing glyph and no default character. This is +known to occur for character number 160 (no-break space) in some +fonts, such as Lucida but Emacs sets the display table for the unibyte +and Latin-1 version of this character to display a space. + +*** Some of the fonts called for in your fontset may not exist on your +X server. Each X11 font covers just a fraction of the characters that Emacs supports. To display the whole range of Emacs characters requires -many different fonts, collected into a fontset. - -If some of the fonts called for in your fontset do not exist on your X -server, then the characters that have no font appear as hollow boxes. -You can remedy the problem by installing additional fonts. +many different fonts, collected into a fontset. You can remedy the +problem by installing additional fonts. The intlfonts distribution includes a full spectrum of fonts that can display all the characters Emacs supports. The etl-unicode collection @@ -748,22 +764,33 @@ of fonts (available from and fonts that can display many Unicode characters; they can also be used by ps-print and ps-mule to print Unicode characters. -Another cause of this for specific characters is fonts which have a -missing glyph and no default character. This is known to occur for -character number 160 (no-break space) in some fonts, such as Lucida -but Emacs sets the display table for the unibyte and Latin-1 version -of this character to display a space. - ** Under X11, some characters appear improperly aligned in their lines. You may have bad X11 fonts; try installing the intlfonts distribution -or the etl-unicode collection (see the previous entry). +or the etl-unicode collection (see above). -** Certain fonts make each line take one pixel more than it "should". +** Under X, an unexpected monospace font is used as the default font. -This is because these fonts contain characters a little taller -than the font's nominal height. Emacs needs to make sure that -lines do not overlap. +When compiled with XFT, Emacs tries to use a default font named +"monospace". This is a "virtual font", which the operating system +(Fontconfig) redirects to a suitable font such as DejaVu Sans Mono. +On some systems, there exists a font that is actually named Monospace, +which takes over the virtual font. This is considered an operating +system bug; see + +http://lists.gnu.org/archive/html/emacs-devel/2008-10/msg00696.html + +If you encounter this problem, set the default font to a specific font +in your .Xresources or initialization file. For instance, you can put +the following in your .Xresources: + +Emacs.font: DejaVu Sans Mono 12 + +** Certain fonts make each line take one pixel more than it should. + +This is because these fonts contain characters a little taller than +the font's nominal height. Emacs needs to make sure that lines do not +overlap. ** Loading fonts is very slow. @@ -813,20 +840,6 @@ One user on a Linux-based GNU system reported that this problem went away with installation of a new X server. The failing server was XFree86 3.1.1. XFree86 3.1.2 works. -** Characters are displayed as empty boxes or with wrong font under X. - -This can occur when two different versions of FontConfig are used. -For example, XFree86 4.3.0 has one version and Gnome usually comes -with a newer version. Emacs compiled with Gtk+ will then use -the newer version. In most cases the problem can be temporarily -fixed by stopping the application that has the error (it can be -Emacs or any other application), removing ~/.fonts.cache-1, -and then start the application again. -If removing ~/.fonts.cache-1 and restarting doesn't help, the -application with problem must be recompiled with the same version -of FontConfig as the rest of the system uses. For KDE, it is -sufficient to recompile Qt. - ** Emacs pauses for several seconds when changing the default font. This has been reported for fvwm 2.2.5 and the window manager of KDE