+dnl CF_ARG_DISABLE version: 3 updated: 1999/03/30 17:24:31
+dnl --------------
+dnl Allow user to disable a normally-on option.
+AC_DEFUN([CF_ARG_DISABLE],
+[CF_ARG_OPTION($1,[$2],[$3],[$4],yes)])dnl
+dnl ---------------------------------------------------------------------------
+dnl CF_ARG_OPTION version: 4 updated: 2010/05/26 05:38:42
+dnl -------------
+dnl Restricted form of AC_ARG_ENABLE that ensures user doesn't give bogus
+dnl values.
+dnl
+dnl Parameters:
+dnl $1 = option name
+dnl $2 = help-string
+dnl $3 = action to perform if option is not default
+dnl $4 = action if perform if option is default
+dnl $5 = default option value (either 'yes' or 'no')
+AC_DEFUN([CF_ARG_OPTION],
+[AC_ARG_ENABLE([$1],[$2],[test "$enableval" != ifelse([$5],no,yes,no) && enableval=ifelse([$5],no,no,yes)
+ if test "$enableval" != "$5" ; then
+ifelse([$3],,[ :]dnl
+,[ $3]) ifelse([$4],,,[
+ else
+ $4])
+ fi],[enableval=$5 ifelse([$4],,,[
+ $4
+])dnl
+ ])])dnl
+dnl ---------------------------------------------------------------------------