bug#30088: 26.0.90; [Emacs 26] Rendering glitch

[Charles A. Roelli]

> Date: Fri, 26 Jan 2018 22:03:03 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> 
> Suggestions for such an entry in PROBLEMS are welcome.

How about:

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index c194ba5..2bd1bbc 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -1939,6 +1939,15 @@ set the 'visible-cursor' variable to nil in your 
~/.emacs:
 Still other way is to change the "cvvis" capability to send the
 "\E[?25h\E[?0c" command.
 
+*** Ubuntu and Fedora display glitch
+
+On some Ubuntu or Fedora systems, when double-buffering is enabled
+(which it is, by default) cosmetic artifacts are visible after certain
+scrolling operations.  Double-buffering can be disabled by adding the
+following line to ~/.emacs:
+
+  (modify-all-frames-parameters '((inhibit-double-buffering . t)))
+
 ** FreeBSD
 
 *** FreeBSD: Getting a Meta key on the console.

?