+2013-11-08 Eli Zaretskii <eliz@gnu.org>
+
+ * display.texi (Truncation): Document that cache-long-scans is now
+ non-nil by default. (Bug#15797)
+
2013-11-05 Eli Zaretskii <eliz@gnu.org>
* lists.texi (Rearrangement): Fix indexing.
over the @code{line-prefix} variable. @xref{Special Properties}.
@end defvar
- If your buffer contains @emph{very} long lines, and you use
-continuation to display them, computing the continuation lines can
-make redisplay slow. The column computation and indentation functions
-also become slow. Then you might find it advisable to set
-@code{cache-long-scans} to @code{t}.
+ If your buffer contains only very short lines, you might find it
+advisable to set @code{cache-long-scans} to @code{nil}.
@defvar cache-long-scans
-If this variable is non-@code{nil}, various indentation and motion
-functions, and Emacs redisplay, cache the results of scanning the
-buffer, and consult the cache to avoid rescanning regions of the buffer
-unless they are modified.
+If this variable is non-@code{nil} (the default), various indentation
+and motion functions, and Emacs redisplay, cache the results of
+scanning the buffer, and consult the cache to avoid rescanning regions
+of the buffer unless they are modified.
-Turning on the cache slows down processing of short lines somewhat.
+Turning off the cache speeds up processing of short lines somewhat.
This variable is automatically buffer-local in every buffer.
@end defvar