Disallow setting 'ambiwidth' to "double" when 'listchars' or 'fillchars'
contains a character that would become double width.
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 5f57ed5..b1539bb 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt* For Vim version 7.3e. Last change: 2010 Aug 01
+*options.txt* For Vim version 7.3e. Last change: 2010 Aug 04
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -665,6 +665,9 @@
"single": Use the same width as characters in US-ASCII. This is
expected by most users.
"double": Use twice the width of ASCII characters.
+ *E834* *E835*
+ The value "double" cannot be used if 'listchars' or 'fillchars'
+ contains a character that would be double width.
There are a number of CJK fonts for which the width of glyphs for
those characters are solely based on how many octets they take in