From b76da7e7a580cfae2827baadf5c15c91a3135b1d Mon Sep 17 00:00:00 2001 From: Po Lu Date: Tue, 8 Feb 2022 21:32:07 +0800 Subject: [PATCH] Document some problems found during testing on various X servers * etc/PROBLEMS (General X problems): Document some problems found during testing on various X servers. --- etc/PROBLEMS | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) diff --git a/etc/PROBLEMS b/etc/PROBLEMS index 2358203c3d3..b0692899e81 100644 --- a/etc/PROBLEMS +++ b/etc/PROBLEMS @@ -1709,6 +1709,65 @@ actual version of libXi installed does not. The solution is to upgrade your libXi binaries to libXi 1.8.0 or later, to correspond with your XInput headers. +*** Requesting a private colormap makes Emacs hang. + +The part of Xlib that provides this feature is broken in modern +incarnations of Xlib, so it cannot possibly work. The solution is to +remove anything that looks like this: + + Emacs.privateColormap: on + +From your X defaults file. Your X server might also provide a +different visual class that will do what you want. You can experiment +with `TrueColor-8', by placing: + + Emacs.visualClass: TrueColor-8 + +In your ~/.Xresources, and loading that file. + +*** Colors messed up on Cairo builds or GTK builds. + +If your display defaults to a visual where pixel values cannot be +directly converted to their corresponding real colors, a build with +Cairo drawing or GTK will display colors incorrectly. This is because +Cairo and GTK foolishly assume that all RGB values can be converted +directly from their individual components, without asking the X server +to allocate the color. + +Your X server might have a different visual which is decomposed and +not colormapped. Try the following in your ~/.Xresources: + + Emacs.visualClass: TrueColor-N + +Where "N" is the bit depth of the visual your X server defaults to. +If that does not work, you lose. Configure Emacs '--without-cairo' +and '--with-x-toolkit=lucid' instead. + +*** GUI widgets don't display on GTK builds, except for scrollbars. + +This can happen if your visual does not have a decomposed colormap, +and your X server has the X rendering extension. + +To solve the problem, disable the X rendering extension on your X +server, or rebuild Emacs without GTK+. + +*** On Accelerated X, the GTK 3 menu bar does not select items. + +The solution is to run Emacs with the environment variable 'GDK_DEBUG' +set to "nograbs", like this (where "..." stands for the other +command-line arguments you intend to pass to Emacs): + + GDK_DEBUG=nograbs emacs ... + +Accelerated X is a proprietary X server. Aside from being +proprietary, it has many other disadvantages, such as not supporting +most recent hardware and most modern extensions to the X protocol. +Consider switching to a free X server, such as X.Org. + +If GTK complains about not being built with support for debugging +options, then there is nothing you can do, except for switching to a +free X server. + * Runtime problems on character terminals *** With X forwarding, mouse highlighting can make Emacs slow. -- 2.39.5