msgset: implement "foreach" calls.

* imap4d/copy.c (copy_env) <src>: Remove. Not needed now.
(size_sum,do_copy): Change to a mu_msgset_message_action_t.
(try_copy,safe_copy): Change signature; use mu_msgset_foreach_message.
* imap4d/fetch.c (_fetch_from_message): Change to a
mu_msgset_message_action_t.
(imap4d_fetch0): Use mu_msgset_foreach_message.
* imap4d/imap4d.h (imap4d_message_action_t): Remove typedef.
(util_foreach_message): Remove. Use mu_msgset_foreach_message.
* imap4d/store.c (_do_store): Change to a mu_msgset_message_action_t.
(imap4d_store0): Use mu_msgset_foreach_message.
* imap4d/util.c (util_foreach_message): Remove.
* include/mailutils/list.h (mu_list_foreach_dir): New proto.
* include/mailutils/msgset.h (mu_msgset_msgno_action_t)
(mu_msgset_message_action_t): New typedefs.
(mu_msgset_negate,mu_msgset_foreach_dir_msgno)
(mu_msgset_foreach_msgno,mu_msgset_foreach_dir_message)
(mu_msgset_foreach_message): New protos.
* libmailutils/list/foreachdir.c: New file.
* libmailutils/list/Makefile.am (liblist_la_SOURCES): Add foreachdir.c.
* libmailutils/list/head.c (mu_list_head): Fix conditional.
* libmailutils/list/tail.c (mu_list_tail): Likewise.
* libmailutils/msgset/foreachmsg.c: New file.
* libmailutils/msgset/foreachnum.c: New file.
* libmailutils/msgset/negate.c: New file.
* libmailutils/msgset/Makefile.am (libmsgset_la_SOURCES): Add
new files.
* libmailutils/msgset/getitr.c (mu_msgset_get_iterator): Call
mu_msgset_aggregate before doing anything.
* libmailutils/msgset/getlist.c (mu_msgset_get_list): Likewise.
* libmailutils/msgset/locate.c (mu_msgset_locate): Likewise.
* libmailutils/msgset/parse.c (parse_msgrange): Remove duplicated
code.
* testsuite/msgset.c: Implement -neg option.

@@ -58,57 +58,35 @@ imap4d_copy (struct imap4d_command *command, imap4d_tokbuf_t tok)
 struct copy_env
 {
   mu_mailbox_t dst;
-  mu_mailbox_t src;
   mu_off_t total;
   int ret;
   char **err_text;
 };
 
 static int
-size_sum (size_t msgno, void *data)
+size_sum (size_t msgno, mu_message_t msg, void *data)
 {
   struct copy_env *env = data;
-  mu_message_t msg = NULL;
   int rc;
   
-  rc = mu_mailbox_get_message (env->src, msgno, &msg);
+  size_t size;
+  rc = mu_message_size (msg, &size);
   if (rc)
     {
-      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_get_message", NULL, rc);
-      env->ret = RESP_NO;
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_message_size", NULL, rc);
+      env->ret = RESP_BAD;
       return MU_ERR_FAILURE;
     }
-  else 
-    {
-      size_t size;
-      rc = mu_message_size (msg, &size);
-      if (rc)
-	{
-	  mu_diag_funcall (MU_DIAG_ERROR, "mu_message_size", NULL, rc);
-	  env->ret = RESP_BAD;
-	  return MU_ERR_FAILURE;
-	}
-      env->total += size;
-    }
+  env->total += size;
   return 0;
 }
 
 static int
-do_copy (size_t msgno, void *data)
+do_copy (size_t msgno, mu_message_t msg, void *data)
 {
   struct copy_env *env = data;
-  mu_message_t msg = NULL;
   int status;
 
-  status = mu_mailbox_get_message (env->src, msgno, &msg);
-  if (status)
-    {
-      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_get_message", NULL,
-		       status);
-      env->ret = RESP_BAD;
-      return MU_ERR_FAILURE;
-    }
-
   imap4d_enter_critical ();
   status = mu_mailbox_append_message (env->dst, msg);
   imap4d_leave_critical ();
@@ -124,14 +102,12 @@ do_copy (size_t msgno, void *data)
 }
 
 static int
-try_copy (mu_mailbox_t dst, mu_mailbox_t src, mu_msgset_t msgset,
-	  char **err_text)
+try_copy (mu_mailbox_t dst, mu_msgset_t msgset, char **err_text)
 {
   int rc;
   struct copy_env env;
 
   env.dst = dst;
-  env.src = src;
   env.total = 0;
   env.ret = RESP_OK;
   env.err_text = err_text;
@@ -139,7 +115,7 @@ try_copy (mu_mailbox_t dst, mu_mailbox_t src, mu_msgset_t msgset,
   *env.err_text = "Operation failed";
 
   /* Check size */
-  rc = util_foreach_message (msgset, size_sum, &env);
+  rc = mu_msgset_foreach_message (msgset, size_sum, &env);
   if (rc)
     return RESP_NO;
   if (env.ret != RESP_OK)
@@ -151,7 +127,7 @@ try_copy (mu_mailbox_t dst, mu_mailbox_t src, mu_msgset_t msgset,
       return RESP_NO;
     }
   env.total = 0;
-  rc = util_foreach_message (msgset, do_copy, &env);
+  rc = mu_msgset_foreach_message (msgset, do_copy, &env);
   quota_update (env.total);
   if (rc)
     return RESP_NO;
@@ -159,8 +135,7 @@ try_copy (mu_mailbox_t dst, mu_mailbox_t src, mu_msgset_t msgset,
 }
   
 static int
-safe_copy (mu_mailbox_t dst, mu_mailbox_t src, mu_msgset_t msgset,
-	   char **err_text)
+safe_copy (mu_mailbox_t dst, mu_msgset_t msgset, char **err_text)
 {
   size_t nmesg;
   int status;
@@ -174,7 +149,7 @@ safe_copy (mu_mailbox_t dst, mu_mailbox_t src, mu_msgset_t msgset,
       return RESP_NO;
     }
 
-  status = try_copy (dst, src, msgset, err_text);
+  status = try_copy (dst, msgset, err_text);
   if (status != RESP_OK)
     {
       size_t maxmesg;
@@ -283,7 +258,7 @@ imap4d_copy0 (imap4d_tokbuf_t tok, int isuid, char **err_text)
 	  mu_list_t msglist;
 	  mu_msgset_get_list (msgset, &msglist);
 	  if (!mu_list_is_empty (msglist))
-	    status = safe_copy (cmbox, mbox, msgset, err_text);
+	    status = safe_copy (cmbox, msgset, err_text);
 	  mu_mailbox_close (cmbox);
 	}
       mu_mailbox_destroy (&cmbox);

@@ -1783,19 +1783,19 @@ fetch_thunk (imap4d_parsebuf_t pb)
 }
 
 int
-_fetch_from_message (size_t msgno, void *data)
+_fetch_from_message (size_t msgno, mu_message_t msg, void *data)
 {
   int rc = 0;
   struct fetch_runtime_closure *frc = data;
 
   frc->msgno = msgno;
-  if (mu_mailbox_get_message (mbox, msgno, &frc->msg) == 0)
-    {
-      io_sendf ("* %lu FETCH (", (unsigned long) msgno);
-      frc->eltno = 0;
-      rc = mu_list_foreach (frc->fnlist, _do_fetch, frc);
-      io_sendf (")\n");
-    }
+  frc->msg = msg;
+
+  io_sendf ("* %lu FETCH (", (unsigned long) msgno);
+  frc->eltno = 0;
+  rc = mu_list_foreach (frc->fnlist, _do_fetch, frc);
+  io_sendf (")\n");
+
   return rc;
 }
 
@@ -1833,7 +1833,7 @@ imap4d_fetch0 (imap4d_tokbuf_t tok, int isuid, char **err_text)
 	 loop below */
       frc.err_text = "Completed";
 
-      util_foreach_message (pclos.msgset, _fetch_from_message, &frc);
+      mu_msgset_foreach_message (pclos.msgset, _fetch_from_message, &frc);
       mu_list_destroy (&frc.msglist);
     }
   

@@ -372,11 +372,6 @@ extern char *util_getfullpath (const char *);
 extern struct imap4d_command *util_getcommand (char *, 
                                                struct imap4d_command []);
 
-typedef int (*imap4d_message_action_t) (size_t, void *);
-
-int util_foreach_message (mu_msgset_t list, imap4d_message_action_t action,
-			  void *data);
-
 enum datetime_parse_mode     /* how to parse date/time strings */
   {
     datetime_default,        /* default mode */

@@ -91,13 +91,11 @@ store_thunk (imap4d_parsebuf_t p)
 }
 
 static int
-_do_store (size_t msgno, void *data)
+_do_store (size_t msgno, mu_message_t msg, void *data)
 {
   struct store_parse_closure *pclos = data;
-  mu_message_t msg = NULL;
   mu_attribute_t attr = NULL;
       
-  mu_mailbox_get_message (mbox, msgno, &msg);
   mu_message_get_attribute (msg, &attr);
 	      
   switch (pclos->how)
@@ -154,7 +152,7 @@ imap4d_store0 (imap4d_tokbuf_t tok, int isuid, char **ptext)
 			     ptext);
   if (rc == RESP_OK)
     {
-      util_foreach_message (pclos.msgset, _do_store, &pclos);
+      mu_msgset_foreach_message (pclos.msgset, _do_store, &pclos);
     
       *ptext = "Completed";
     }

@@ -39,42 +39,6 @@ util_getfullpath (const char *name)
   return mu_normalize_path (exp);
 }
 
-struct action_closure
-{
-  imap4d_message_action_t action;
-  void *data;
-};
-
-static int
-procrange (void *item, void *data)
-{
-  struct mu_msgrange *mp = item;
-  struct action_closure *clos = data;
-  size_t i;
-
-  for (i = mp->msg_beg; i <= mp->msg_end; i++)
-    {
-      int rc = clos->action (i, clos->data);
-      if (rc)
-	return rc;
-    }
-  return 0;
-}
-
-/* Apply ACTION to each message number from LIST. */
-int
-util_foreach_message (mu_msgset_t msgset, imap4d_message_action_t action,
-		      void *data)
-{
-  mu_list_t list;
-  struct action_closure clos;
-  
-  clos.action = action;
-  clos.data = data;
-  mu_msgset_get_list (msgset, &list);
-  return mu_list_foreach (list, procrange, &clos);
-}
-
 int
 util_do_command (imap4d_tokbuf_t tok)
 {

@@ -144,10 +144,15 @@ int mu_list_get_iterator (mu_list_t _list, mu_iterator_t *_pitr);
 typedef int (*mu_list_action_t) (void *_item, void *_data);
 
   /* Execute _action for each element in _list.  Use _data as the call-specific
-     data. */
+     data.  If _dir is 0, traverse the list from head to tail.  If it is 1,
+     traverse it in the reverse direction */
+int mu_list_foreach_dir (mu_list_t _list, int _dir, mu_list_action_t _action,
+			 void *_cbdata);
+  /* Same as mu_list_foreach_dir with _dir==0. */
 int mu_list_foreach (mu_list_t _list, mu_list_action_t _action, void *_data);
   /* A historical alias to the above. */
 int mu_list_do (mu_list_t, mu_list_action_t, void *) MU_DEPRECATED;
+  
 
   /* ************************************************* */
   /* Functions for combining two lists.                */

@@ -33,7 +33,7 @@ struct mu_msgrange
 #define MU_MSGNO_LAST   0
   
 #define MU_MSGSET_UID   0x01   /* Message set operates on UIDs */
-  
+
 int mu_msgset_create (mu_msgset_t *pmsgset, mu_mailbox_t mbox, int flags);
 int mu_msgset_get_list (mu_msgset_t msgset, mu_list_t *plist);
 int mu_msgset_get_iterator (mu_msgset_t msgset, mu_iterator_t *pitr);
@@ -53,6 +53,26 @@ int mu_msgset_print (mu_stream_t str, mu_msgset_t msgset);
   
 int mu_msgset_locate (mu_msgset_t msgset, size_t n,
 		      struct mu_msgrange const **prange);
+
+int mu_msgset_negate (mu_msgset_t msgset, mu_msgset_t *pnset);
+  
+typedef int (*mu_msgset_msgno_action_t) (size_t _n, void *_call_data);
+typedef int (*mu_msgset_message_action_t) (size_t _n, mu_message_t _msg,
+					   void *_call_data);
+
+int mu_msgset_foreach_dir_msgno (mu_msgset_t _msgset, int _dir,
+				 mu_msgset_msgno_action_t _action,
+				 void *_data);
+int mu_msgset_foreach_msgno (mu_msgset_t _msgset,
+			     mu_msgset_msgno_action_t _action,
+			     void *_call_data);
+int mu_msgset_foreach_dir_message (mu_msgset_t _msgset, int _dir,
+				   mu_msgset_message_action_t _action,
+				   void *_call_data);
+int mu_msgset_foreach_message (mu_msgset_t _msgset,
+			       mu_msgset_message_action_t _action,
+			       void *_call_data);
+
   
 #ifdef __cplusplus
 }

@@ -29,6 +29,7 @@ liblist_la_SOURCES = \
  foreach.c\
  get.c\
  getcomp.c\
+ foreachdir.c\
  gmap.c\
  head.c\
  insert.c\

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 1999, 2000, 2001, 2004, 2005, 2007, 2008, 2010, 2011
+   Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <stdlib.h>
+#include <mailutils/sys/list.h>
+#include <mailutils/errno.h>
+
+int
+mu_list_foreach_dir (mu_list_t list, int dir,
+		     mu_list_action_t action, void *cbdata)
+{
+  mu_iterator_t itr;
+  int status = 0;
+  
+  if (list == NULL || action == NULL)
+    return EINVAL;
+  status = mu_list_get_iterator (list, &itr);
+  if (status)
+    return status;
+
+  status = mu_iterator_ctl (itr, mu_itrctl_set_direction, &dir);
+  if (status == 0)
+    for (mu_iterator_first (itr); !mu_iterator_is_done (itr);
+	 mu_iterator_next (itr))
+      {
+	void *item;
+	mu_iterator_current (itr, &item);
+	if ((status = action (item, cbdata)))
+	  break;
+      }
+  mu_iterator_destroy (&itr);
+  return status;
+}
+

@@ -29,7 +29,7 @@ mu_list_head (mu_list_t list, void **pitem)
     return EINVAL;
   if (pitem == NULL)
     return MU_ERR_OUT_PTR_NULL;
-  if (!list->head.next)
+  if (list->head.next == &list->head)
     return MU_ERR_NOENT;
   *pitem = list->head.next->item;
   return 0;

@@ -29,7 +29,7 @@ mu_list_tail (mu_list_t list, void **pitem)
     return EINVAL;
   if (pitem == NULL)
     return MU_ERR_OUT_PTR_NULL;
-  if (!list->head.prev)
+  if (list->head.prev == &list->head)
     return MU_ERR_NOENT;
   *pitem = list->head.prev->item;
   return 0;

@@ -24,8 +24,11 @@ libmsgset_la_SOURCES = \
  create.c\
  getitr.c\
  getlist.c\
+ foreachnum.c\
+ foreachmsg.c\
  free.c\
  locate.c\
+ negate.c\
  parse.c\
  print.c\
  sub.c

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   GNU Mailutils is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GNU Mailutils is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+#include <stdlib.h>
+#include <mailutils/types.h>
+#include <mailutils/errno.h>
+#include <mailutils/list.h>
+#include <mailutils/msgset.h>
+#include <mailutils/mailbox.h>
+#include <mailutils/sys/msgset.h>
+
+struct action_closure
+{
+  mu_msgset_message_action_t action;
+  void *data;
+  mu_msgset_t msgset;
+  int dir;
+};
+
+static int
+procrange (void *item, void *data)
+{
+  struct mu_msgrange *mp = item;
+  struct action_closure *clos = data;
+  size_t i;
+
+  if (clos->dir)
+    for (i = mp->msg_end; i >= mp->msg_beg; i--)
+      {
+	int rc;
+	mu_message_t msg = NULL;
+	
+	if (clos->msgset->mbox)
+	  {
+	    rc = mu_mailbox_get_message (clos->msgset->mbox, i, &msg);
+	    if (rc == MU_ERR_NOENT)
+	      continue;
+	    else if (rc)
+	    return rc;
+	  }
+	rc = clos->action (i, msg, clos->data);
+	if (rc)
+	  return rc;
+      }
+  else
+    for (i = mp->msg_beg; i <= mp->msg_end; i++)
+      {
+	int rc;
+	mu_message_t msg = NULL;
+	
+	if (clos->msgset->mbox)
+	  {
+	    rc = mu_mailbox_get_message (clos->msgset->mbox, i, &msg);
+	    if (rc == MU_ERR_NOENT)
+	      continue;
+	    else if (rc)
+	      return rc;
+	  }
+	rc = clos->action (i, msg, clos->data);
+	if (rc)
+	  return rc;
+      }
+  return 0;
+}
+
+/* Apply ACTION to each message number from MSGSET. */
+int
+mu_msgset_foreach_dir_message (mu_msgset_t msgset, int dir,
+			       mu_msgset_message_action_t action,
+			       void *data)
+{
+  int rc;
+  struct action_closure clos;
+  
+  rc = mu_msgset_aggregate (msgset);
+  if (rc)
+    return rc;
+  clos.action = action;
+  clos.data = data;
+  clos.msgset = msgset;
+  clos.dir = dir;
+  return mu_list_foreach_dir (msgset->list, dir, procrange, &clos);
+}
+
+int
+mu_msgset_foreach_message (mu_msgset_t msgset,
+			   mu_msgset_message_action_t action,
+			   void *data)
+{
+  return mu_msgset_foreach_dir_message (msgset, 0, action, data);
+}

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   GNU Mailutils is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GNU Mailutils is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+#include <stdlib.h>
+#include <mailutils/types.h>
+#include <mailutils/errno.h>
+#include <mailutils/list.h>
+#include <mailutils/msgset.h>
+#include <mailutils/sys/msgset.h>
+
+struct action_closure
+{
+  mu_msgset_msgno_action_t action;
+  void *data;
+  mu_msgset_t msgset;
+  int dir;
+};
+
+static int
+procrange (void *item, void *data)
+{
+  struct mu_msgrange *mp = item;
+  struct action_closure *clos = data;
+  size_t i;
+
+  if (clos->dir)
+    for (i = mp->msg_end; i >= mp->msg_beg; i--)
+      {
+	int rc = clos->action (i, clos->data);
+	if (rc)
+	  return rc;
+      }
+  else
+    for (i = mp->msg_beg; i <= mp->msg_end; i++)
+      {
+	int rc = clos->action (i, clos->data);
+	if (rc)
+	  return rc;
+      }
+  return 0;
+}
+
+/* Apply ACTION to each message number from MSGSET. */
+int
+mu_msgset_foreach_dir_msgno (mu_msgset_t msgset, int dir,
+			     mu_msgset_msgno_action_t action,
+			     void *data)
+{
+  int rc;
+  struct action_closure clos;
+  
+  rc = mu_msgset_aggregate (msgset);
+  if (rc)
+    return rc;
+  clos.action = action;
+  clos.data = data;
+  clos.dir = dir;
+  return mu_list_foreach_dir (msgset->list, dir, procrange, &clos);
+}
+
+int
+mu_msgset_foreach_msgno (mu_msgset_t msgset,
+			 mu_msgset_msgno_action_t action,
+			 void *data)
+{
+  return mu_msgset_foreach_dir_msgno (msgset, 0, action, data);
+}

@@ -24,7 +24,11 @@
 int
 mu_msgset_get_iterator (mu_msgset_t msgset, mu_iterator_t *pitr)
 {
+  int rc;
   if (!msgset)
     return EINVAL;
+  rc = mu_msgset_aggregate (msgset);
+  if (rc)
+    return rc;
   return mu_list_get_iterator (msgset->list, pitr);
 }

@@ -24,10 +24,14 @@
 int
 mu_msgset_get_list (mu_msgset_t msgset, mu_list_t *plist)
 {
+  int rc;
   if (!msgset)
     return EINVAL;
   if (!plist)
     return MU_ERR_OUT_PTR_NULL;
+  rc = mu_msgset_aggregate (msgset);
+  if (rc)
+    return rc;
   *plist = msgset->list;
   return 0;
 }

@@ -26,7 +26,11 @@ int
 mu_msgset_locate (mu_msgset_t msgset, size_t n,
 		  struct mu_msgrange const **prange)
 {
+  int rc;
   if (!msgset || n == 0)
     return EINVAL;
+  rc = mu_msgset_aggregate (msgset);
+  if (rc)
+    return rc;
   return mu_list_locate (msgset->list, &n, (void**)prange);
 }

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   GNU Mailutils is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GNU Mailutils is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+#include <stdlib.h>
+#include <mailutils/types.h>
+#include <mailutils/errno.h>
+#include <mailutils/list.h>
+#include <mailutils/mailbox.h>
+#include <mailutils/msgset.h>
+#include <mailutils/sys/msgset.h>
+
+struct invert_closure
+{
+  mu_msgset_t nset;
+  size_t next_num;
+};
+
+static int
+_invert_range (void *item, void *data)
+{
+  struct mu_msgrange *range = item;
+  struct invert_closure *clos = data;
+  int rc;
+  
+  if (clos->next_num < range->msg_beg - 1)
+    {
+      rc = mu_msgset_add_range (clos->nset, clos->next_num, range->msg_beg - 1);
+      if (rc)
+	return rc;
+    }
+  clos->next_num = range->msg_end + 1;
+  return 0;
+}
+
+/* Negate the message set: on return PNSET consists of the messages
+   _not contained_ in the input message set. */
+int
+mu_msgset_negate (mu_msgset_t msgset, mu_msgset_t *pnset)
+{
+  int rc;
+  struct invert_closure clos;
+  size_t total;
+  
+  if (!msgset)
+    return EINVAL;
+  if (!msgset->mbox)
+    return MU_ERR_NOT_OPEN;
+
+  rc = mu_msgset_aggregate (msgset);
+  if (rc)
+    return rc;
+  rc = mu_mailbox_messages_count (msgset->mbox, &total);
+  if (rc)
+    return rc;
+  rc = mu_msgset_create (&clos.nset, NULL, 0);
+  if (rc)
+    return rc;
+  clos.next_num = 1;
+  rc = mu_list_foreach (msgset->list, _invert_range, &clos);
+  if (rc == 0)
+    {
+      if (clos.next_num < total)
+	rc = mu_msgset_add_range (clos.nset, clos.next_num, total);
+    }
+  
+  if (rc)
+    mu_msgset_free (clos.nset);
+  else
+    {
+      clos.nset->mbox = msgset->mbox;
+      *pnset = clos.nset;
+    }
+  return 0;
+}

@@ -101,14 +101,6 @@ parse_msgrange (struct parse_msgnum_env *env)
 
       rc = mu_mailbox_translate (env->msgset->mbox,
 				 MU_MAILBOX_UID_TO_MSGNO,
-				 msgrange.msg_beg, &msgrange.msg_beg);
-      if (rc == MU_ERR_NOENT)
-	msgrange.msg_beg = env->minval;
-      else if (rc)
-	return rc;
-      
-      rc = mu_mailbox_translate (env->msgset->mbox,
-				 MU_MAILBOX_UID_TO_MSGNO,
 				 msgrange.msg_end, &msgrange.msg_end);
       if (rc == MU_ERR_NOENT)
 	msgrange.msg_end = env->maxval;

@@ -117,6 +117,13 @@ main (int argc, char **argv)
 	  MU_ASSERT (mu_msgset_sub_range (msgset, range.msg_beg,
 					  range.msg_end));
 	}
+      else if (strcmp (arg, "-neg") == 0)
+	{
+	  mu_msgset_t negated_set;
+	  MU_ASSERT (mu_msgset_negate (msgset, &negated_set));
+	  mu_msgset_free (msgset);
+	  msgset = negated_set;
+	}
       else
       	{
 	  mu_error ("unknown option %s", arg);