Document redisplay-skip-fontification-on-input

* doc/emacs/display.texi (Scrolling): Mention
redisplay-skip-fontification-on-input.

diff --git a/doc/emacs/display.texi b/doc/emacs/display.texi
index 996c5a665475a451dacfd917348296d97d97e0b3..7ea754612eedd5a21255208477b2320a8c198878 100644 (file)
--- a/doc/emacs/display.texi
+++ b/doc/emacs/display.texi
@@ -150,6 +150,14 @@ gives you less jerky scrolling when you hold down @kbd{C-v}, but the
 window contents after any action which scrolls into a fresh portion of
 the buffer will be momentarily unfontified.
 
+@vindex redisplay-skip-fontification-on-input
+Finally, a third alternative to these variables is
+@code{redisplay-skip-fontification-on-input}.  If this variable is
+non-@code{nil}, skip some fontifications is there's input pending.
+This usually does not affect the display because redisplay is
+completely skipped anyway if input was pending, but it can make
+scrolling smoother by avoiding unnecessary fontification.
+
 @vindex scroll-up
 @vindex scroll-down
 @findex scroll-up-line

diff --git a/etc/NEWS b/etc/NEWS
index 32982122e28ea9b3e6cc6bc7d988691e24a48e54..1ee85883756848f77e11b93b94cf633b40273ad9 100644 (file)
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -745,6 +745,7 @@ Applies to headings of shortdoc sections.
 *** New face 'separator-line'.
 This is used by 'make-separator-line' (see below).
 
++++
 *** 'redisplay-skip-fontification-on-input' helps Emacs keep up with fast input.
 This is another attempt to solve the problem of handling high key repeat rate
 and other "slow scrolling" situations.  It is hoped it behaves better