Bugfix

* configure.ac: Version 2.99.992
* NEWS: Update.
* libmailutils/opt/opt.c (add_option_cache): Use opt_default if
no argument is given.

-GNU mailutils NEWS -- history of user-visible changes. 2016-10-19
+GNU mailutils NEWS -- history of user-visible changes. 2016-10-28
 Copyright (C) 2002-2016 Free Software Foundation, Inc.
 See the end of file for copying conditions.
 
 Please send mailutils bug reports to <bug-mailutils@gnu.org>.
 
 
-Version 2.99.991 (Git)
+Version 2.99.992 (Git)
 
 This version is a major rewrite of GNU Mailutils.  Quite a few parts
 of the basic framework were rewritten from scratch, while some others

@@ -16,7 +16,7 @@ dnl You should have received a copy of the GNU General Public License along
 dnl with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
 
 AC_PREREQ(2.63)
-AC_INIT([GNU Mailutils], [2.99.991], [bug-mailutils@gnu.org], [mailutils],
+AC_INIT([GNU Mailutils], [2.99.992], [bug-mailutils@gnu.org], [mailutils],
         [http://mailutils.org])
 AC_CONFIG_SRCDIR([libmailutils/mailbox/mailbox.c])
 AC_CONFIG_AUX_DIR([build-aux])

@@ -148,7 +148,10 @@ add_option_cache (struct mu_parseopt *po, struct mu_option *opt,
 		  char const *arg)
 {
   struct mu_option_cache *cache = mu_alloc (sizeof (*cache));
+  
   cache->cache_opt = opt;
+  if (arg == NULL && opt->opt_default)
+    arg = opt->opt_default;
   cache->cache_arg = arg;
 
   if ((po->po_flags & MU_PARSEOPT_IMMEDIATE)
@@ -749,6 +752,9 @@ mu_option_set_value (struct mu_parseopt *po, struct mu_option *opt,
       if (arg == NULL)
 	{
 	  if (opt->opt_default)
+	    /* The default value has been already assigned in add_option_cache.
+	       This conditional is here in case mu_option_set_value is called
+	       from the user code. */
 	    arg = opt->opt_default;
 	  else if (opt->opt_arg == NULL)
 	    arg = "1";