mention DUALCASE

[Ralf Wildenhues]

Autoconf needs to mention all variables which are used by configure and
are not in the ac_* namespace.

Regards,
Ralf

        * doc/autoconf.texi (Special Shell Variables): Mention DUALCASE.

Index: doc/autoconf.texi
===================================================================
RCS file: /cvsroot/autoconf/autoconf/doc/autoconf.texi,v
retrieving revision 1.870
diff -u -r1.870 autoconf.texi
--- doc/autoconf.texi   1 Feb 2005 00:36:24 -0000       1.870
+++ doc/autoconf.texi   1 Feb 2005 14:04:50 -0000
@@ -10422,6 +10422,12 @@
 Autoconf-generated scripts automatically unset @code{CDPATH} if
 possible, so you need not worry about this problem in those scripts.
 
address@hidden DUALCASE
address@hidden DUALCASE
+Case statements are matched case-insensitively by the MKS shell unless
+this variables is set to 1.  @command{configure} exports this when it
+starts up.
+
 @item IFS
 @evindex IFS
 Don't set the first character of @code{IFS} to backslash.  Indeed,