Provide a library function for translating message UIDs to numbers and vice versa.

* include/mailutils/mailbox.h (MU_MAILBOX_UID_TO_MSGNO)
(MU_MAILBOX_MSGNO_TO_UID): New defines.
(mu_mailbox_translate): New proto.
* include/mailutils/sys/mailbox.h (_mu_mailbox) <_translate>: New
method.
* libmailutils/mailbox/mailbox.c (mu_mailbox_translate): New
function.
* libproto/mh/mbox.c (mh_translate): New function.  Implements
the _translate method.
* mh/mh_msgset.c (mh_uid_to_msgno, mh_msgno_to_uid): Remove.  All
callers updated to use mu_mailbox_translate instead.
(mh_search_message): Remove.
(mh_get_message): Rewrite using mu_mailbox_translate.

* mh/comp.c (copy_message): Check return from mu_mailbox_get_message.
* mh/mh_init.c (mh_draft_message): Rewrite using mu_url_sget_path.
* mh/tests/comp.at: Test draftfolder functionality.

@@ -116,6 +116,12 @@ extern int mu_mailbox_unlock (mu_mailbox_t mbox);
 
 extern int mu_mailbox_get_iterator (mu_mailbox_t mbx,
 				    mu_iterator_t *piterator);
+
+/* ID translation */
+#define MU_MAILBOX_UID_TO_MSGNO 0
+#define MU_MAILBOX_MSGNO_TO_UID 1
+
+extern int mu_mailbox_translate (mu_mailbox_t, int, size_t, size_t *);  
   
 #ifdef __cplusplus
 }

@@ -74,6 +74,8 @@ struct _mu_mailbox
 
   int  (*_quick_get_message) (mu_mailbox_t, mu_message_qid_t, mu_message_t *);
   int  (*_get_uidls) (mu_mailbox_t, mu_list_t);
+
+  int  (*_translate) (mu_mailbox_t, int cmd, size_t, size_t *);
 };
 
 # ifdef __cplusplus

@@ -167,7 +167,7 @@ amd_msg_bsearch (struct _amd_data *amd, mu_off_t first, mu_off_t last,
 
 /* Search for message MSG in the message array of AMD.
    If found, return 0 and store index of the located entry in the
-   variable PRET. Otherwise, return 1 and place into PRET index of
+   variable PRET. Otherwise, return 1 and store in PRET the index of
    the array element that is less than MSG (in the sense of
    amd->msg_cmp)
    Index returned in PRET is 1-based, so *PRET == 0 means that MSG

@@ -829,4 +829,116 @@ mu_mailbox_get_uidls (mu_mailbox_t mbox, mu_list_t *plist)
   return status;
 }
 
+
+/* Auxiliary function. Performs binary search for a message with the
+   given UID number */
+static int
+_uid_bsearch (mu_mailbox_t mbox, size_t start, size_t stop, size_t uid,
+	      size_t *msgno)
+{
+  mu_message_t mid_msg = NULL;
+  size_t num = 0, middle;
+  int rc;
+  
+  middle = (start + stop) / 2;
+  rc = mu_mailbox_get_message (mbox, middle, &mid_msg);
+  if (rc)
+    return rc;
+  rc = mu_message_get_uid (mid_msg, &num);
+  if (rc)
+    return rc;
+
+  if (num == uid)
+    {
+      *msgno = middle;
+      return 0;
+    }
+      
+  if (start >= stop)
+    return MU_ERR_NOENT;
+
+  if (num > uid)
+    return _uid_bsearch (mbox, start, middle - 1, uid, msgno);
+  else /*if (num < seqno)*/
+    return _uid_bsearch (mbox, middle + 1, stop, uid, msgno);
+}
+
+static int
+_search_message_uid (mu_mailbox_t mbox, size_t uid, size_t *result)
+{
+  int rc;
+  size_t num, count;
+  mu_message_t msg;
+
+  rc = mu_mailbox_get_message (mbox, 1, &msg);
+  if (rc)
+    return rc;
+  rc = mu_message_get_uid (msg, &num);
+  if (rc)
+    return rc;
+  if (uid < num)
+    return MU_ERR_NOENT;
+  else if (uid == num)
+    {
+      *result = 1;
+      return 0;
+    }
+
+  rc = mu_mailbox_messages_count (mbox, &count);
+  if (rc)
+    return rc;
+  rc = mu_mailbox_get_message (mbox, count, &msg);
+  if (rc)
+    return rc;
+  rc = mu_message_get_uid (msg, &num);
+  if (rc)
+    return rc;
+
+  if (uid > num)
+    return MU_ERR_NOENT;
+  else if (uid == num)
+    {
+      *result = count;
+      return 0;
+    }
+  return _uid_bsearch (mbox, 1, count, uid, result);
+}
+
+/* Translat message UIDs to message numbers and vice versa. */
+int
+mu_mailbox_translate (mu_mailbox_t mbox, int cmd, size_t from, size_t *to)
+{
+  int rc = ENOSYS;
+  mu_message_t msg;
+  
+  if (mbox == NULL)
+    return MU_ERR_MBX_NULL;
+  if (to == NULL)
+    return EINVAL;
+  if (mbox->flags & MU_STREAM_QACCESS)
+    return MU_ERR_BADOP;
+
+  if (mbox->_translate)
+    rc = mbox->_translate (mbox, cmd, from, to);
+  if (rc == ENOSYS)
+    {
+      switch (cmd)
+	{
+	case MU_MAILBOX_UID_TO_MSGNO:
+	  rc = _search_message_uid (mbox, from, to);
+	  break;
+	  
+	case MU_MAILBOX_MSGNO_TO_UID:
+	  rc = mu_mailbox_get_message (mbox, from, &msg);
+	  if (rc)
+	    return rc;
+	  rc = mu_message_get_uid (msg, to);
+	  break;
 	  
+	default:
+	  break;
+	}
+    }
+  return rc;
+}
+

@@ -51,6 +51,7 @@
 #include <mailutils/debug.h>
 #include <mailutils/envelope.h>
 #include <mailutils/error.h>
+#include <mailutils/errno.h>
 #include <mailutils/header.h>
 #include <mailutils/locker.h>
 #include <mailutils/message.h>
@@ -380,6 +381,39 @@ mh_get_property (mu_mailbox_t mailbox, mu_property_t *pprop)
   return 0;
 }
 
+
+
+static int
+mh_translate (mu_mailbox_t mbox, int cmd, size_t from, size_t *to)
+{
+  struct _amd_data *amd = mbox->data;
+  struct _mh_message msg, *mp;
+  size_t n;
+
+  /* Make sure the mailbox has been scanned */ 
+  mu_mailbox_messages_count (mbox, &n);
+    
+  switch (cmd)
+    {
+    case MU_MAILBOX_UID_TO_MSGNO:
+      msg.seq_number = from;
+      if (amd_msg_lookup (amd, (struct _amd_message*) &msg, &n))
+	return MU_ERR_NOENT;
+      *to = n;
+      break;
+
+    case MU_MAILBOX_MSGNO_TO_UID:
+      mp = (struct _mh_message *) _amd_get_message (amd, from);
+      if (!mp)
+	return MU_ERR_NOENT;
+      *to = mp->seq_number;
+      break;
+
+    default:
+      return ENOSYS;
+    }
+  return 0;
+}
 
 
 
@@ -407,6 +441,7 @@ _mailbox_mh_init (mu_mailbox_t mailbox)
   amd->remove = mh_remove;
 
   mailbox->_get_property = mh_get_property;
+  mailbox->_translate = mh_translate;
   
   return 0;
 }

@@ -161,7 +161,13 @@ copy_message (mu_mailbox_t mbox, size_t n, const char *file)
   mu_stream_t out;
   int rc;
   
-  mu_mailbox_get_message (mbox, n, &msg);
+  rc = mu_mailbox_get_message (mbox, n, &msg);
+  if (rc)
+    {
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_get_message", NULL, rc);
+      exit (1);
+    }
+  
   mu_message_get_streamref (msg, &in);
   
   if ((rc = mu_file_stream_create (&out,

@@ -970,15 +970,14 @@ mh_draft_message (const char *name, const char *msgspec, char **pname)
   mu_url_t url;
   size_t uid;
   int rc;
-  const char *urlstr;
   mu_mailbox_t mbox;
-
+  const char *path;
+  
   mbox = mh_open_folder (name, 0);
   if (!mbox)
     return 1;
   
   mu_mailbox_get_url (mbox, &url);
-  urlstr = mu_url_to_string (url);
 
   if (strcmp (msgspec, "new") == 0)
     {
@@ -986,8 +985,11 @@ mh_draft_message (const char *name, const char *msgspec, char **pname)
       
       rc = mu_mailbox_uidnext (mbox, &uid);
       if (rc)
-	mu_error (_("cannot obtain sequence number for the new message: %s"),
-		  mu_strerror (rc));
+	{
+	  mu_error (_("cannot obtain sequence number for the new message: %s"),
+		    mu_strerror (rc));
+	  exit (1);
+	}
       mu_mailbox_get_property (mbox, &prop);
       mu_property_set_value (prop, "cur", mu_umaxtostr (0, uid), 1);
     }
@@ -1008,21 +1010,13 @@ mh_draft_message (const char *name, const char *msgspec, char **pname)
 	}
       mh_msgset_free (&msgset);
     }
-  
-  if (rc == 0)
+
+  mu_url_sget_path (url, &path);
+  rc = mu_asprintf (pname, "%s/%lu", path, (unsigned long) uid);
+  if (rc)
     {
-      const char *dir;
-      const char *msg;
-      size_t len;
-      
-      dir = urlstr + 3; /* FIXME */
-      
-      msg = mu_umaxtostr (0, uid);
-      len = strlen (dir) + 1 + strlen (msg) + 1;
-      *pname = xmalloc (len);
-      strcpy (*pname, dir);
-      strcat (*pname, "/");
-      strcat (*pname, msg);
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_asprintf", NULL, rc);
+      exit (1);
     }
   mu_mailbox_close (mbox);
   mu_mailbox_destroy (&mbox);

@@ -19,27 +19,6 @@
 
 #include <mh.h>
 
-int
-mh_uid_to_msgno (mu_mailbox_t mbox, size_t uid, size_t *msgno)
-{
-  size_t num = mh_get_message (mbox, uid, NULL);
-  if (num == 0)
-    return MU_ERR_NOENT;
-  *msgno = num;
-  return 0;
-}
-
-int
-mh_msgno_to_uid (mu_mailbox_t mbox, size_t msgno, size_t *uid)
-{
-  mu_message_t msg;
-  int rc = mu_mailbox_get_message (mbox, msgno, &msg);
-  if (rc)
-    return rc;
-  return mu_message_get_uid (msg, uid);
-}
-
-
 void
 mh_msgset_init (mh_msgset_t *msgset)
 {
@@ -196,75 +175,6 @@ mh_msgset_uids (mu_mailbox_t mbox, mh_msgset_t *msgset)
     }
   msgset->flags |= MH_MSGSET_UID;
 }
-
-/* Auxiliary function. Performs binary search for a message with the
-   given sequence number */
-static size_t
-mh_search_message (mu_mailbox_t mbox, size_t start, size_t stop,
-		   size_t seqno, mu_message_t *mesg)
-{
-  mu_message_t mid_msg = NULL;
-  size_t num = 0, middle;
-
-  middle = (start + stop) / 2;
-  if (mu_mailbox_get_message (mbox, middle, &mid_msg)
-      || mh_message_number (mid_msg, &num))
-    return 0;
-
-  if (num == seqno)
-    {
-      if (mesg)
-	*mesg = mid_msg;
-      return middle;
-    }
-      
-  if (start >= stop)
-    return 0;
-
-  if (num > seqno)
-    return mh_search_message (mbox, start, middle-1, seqno, mesg);
-  else /*if (num < seqno)*/
-    return mh_search_message (mbox, middle+1, stop, seqno, mesg);
-}
-
-/* Retrieve the message with the given sequence number.
-   Returns ordinal number of the message in the mailbox if found,
-   zero otherwise. The retrieved message is stored in the location
-   pointed to by mesg, unless it is NULL. */
-   
-size_t
-mh_get_message (mu_mailbox_t mbox, size_t seqno, mu_message_t *mesg)
-{
-  size_t num, count;
-  mu_message_t msg;
-
-  if (mu_mailbox_get_message (mbox, 1, &msg)
-      || mh_message_number (msg, &num))
-    return 0;
-  if (seqno < num)
-    return 0;
-  else if (seqno == num)
-    {
-      if (mesg)
-	*mesg = msg;
-      return 1;
-    }
-
-  if (mu_mailbox_messages_count (mbox, &count)
-      || mu_mailbox_get_message (mbox, count, &msg)
-      || mh_message_number (msg, &num))
-    return 0;
-  if (seqno > num)
-    return 0;
-  else if (seqno == num)
-    {
-      if (mesg)
-	*mesg = msg;
-      return count;
-    }
-
-  return mh_search_message (mbox, 1, count, seqno, mesg);
-}
 
 
 struct msgset_parser
@@ -415,7 +325,7 @@ msgset_cur (mu_mailbox_t mbox, size_t *pnum)
 {
   size_t num;
   mh_mailbox_get_cur (mbox, &num);
-  return mh_uid_to_msgno (mbox, num, pnum);
+  return mu_mailbox_translate (mbox, MU_MAILBOX_UID_TO_MSGNO, num, pnum);
 }
 
 static int
@@ -518,7 +428,8 @@ parse_term (struct msgset_parser *parser, int seq)
       if (endp != parser->curp)
 	msgset_abort (term);
       
-      if (mh_uid_to_msgno (parser->mbox, num, &parser->number))
+      if (mu_mailbox_translate (parser->mbox, MU_MAILBOX_UID_TO_MSGNO,
+				num, &parser->number))
 	{
 	  parser->validuid = 0;
 	  parser->number = num;
@@ -617,7 +528,8 @@ parse_range (struct msgset_parser *parser)
 	{
 	  size_t total, lastuid;
 	  msgset_last (parser->mbox, &total);
-	  mh_msgno_to_uid (parser->mbox, total, &lastuid);
+	  mu_mailbox_translate (parser->mbox, MU_MAILBOX_MSGNO_TO_UID,
+				total, &lastuid);
 	  if (start > lastuid)
 	    {
 	      if (!parser->sign)
@@ -647,7 +559,9 @@ parse_range (struct msgset_parser *parser)
 	  size_t total;
 
 	  msgset_last (parser->mbox, &total);
-	  mh_msgno_to_uid (parser->mbox, total, &lastuid);
+	  mu_mailbox_translate (parser->mbox, MU_MAILBOX_MSGNO_TO_UID,
+				total, &lastuid);
+
 	  if (parser->number > lastuid)
 	    parser->number = total;
 	  else if (!validuid)
@@ -659,7 +573,8 @@ parse_range (struct msgset_parser *parser)
 	    {
 	      size_t total;
 	      msgset_last (parser->mbox, &total);
-	      mh_msgno_to_uid (parser->mbox, total, &lastuid);
+	      mu_mailbox_translate (parser->mbox, MU_MAILBOX_MSGNO_TO_UID,
+				    total, &lastuid);
 	    }
 	  if (start > lastuid && !parser->validuid)
 	    emptyrange_abort (parser->argv[-1]);
@@ -720,3 +635,29 @@ mh_msgset_parse (mu_mailbox_t mbox, mh_msgset_t *msgset,
 
   mh_msgset_optimize (msgset);
 }
+
+
+/* Retrieve the message with the given sequence number.
+   Returns ordinal number of the message in the mailbox if found,
+   zero otherwise. The retrieved message is stored in the location
+   pointed to by mesg, unless it is NULL. */
+   
+size_t
+mh_get_message (mu_mailbox_t mbox, size_t seqno, mu_message_t *mesg)
+{
+  int rc;
+  size_t num;
+
+  if (mu_mailbox_translate (mbox, MU_MAILBOX_UID_TO_MSGNO, seqno, &num))
+    return 0;
+  if (mesg)
+    {
+      rc = mu_mailbox_get_message (mbox, num, mesg);
+      if (rc)
+	{
+	  mu_diag_funcall (MU_DIAG_ERROR, "mu_mailbox_get_message", NULL, rc);
+	  exit (1);
+	}
+    }
+  return num;
+}

@@ -143,6 +143,61 @@ Subject: test input
 message body
 ])
 
+MH_CHECK([comp -draftfolder],[comp05 comp-draftfolder],[
+mkdir Mail/drafts
+dir=`pwd`
+echo 'quit' | compcmd -draftfolder drafts | sed "s|$dir/*||;s|  *$||"
+cat Mail/drafts/1
+],
+[0],
+[-- Editor invocation: Mail/drafts/1
+-- Input file:
+To:
+cc:
+Subject:
+--------
+-- Input file end
+What now? draft left on "Mail/drafts/1".
+To:
+cc:
+Subject:
+--------
+Seen by mhed
+])
+
+MH_CHECK([comp +draftfolder -use],[comp06 comp-draftfolder-use],[
+mkdir Mail/drafts
+AT_DATA([Mail/drafts/1],[From: gray
+To: root
+Subject: test input
+
+message body
+])
+echo "cur: 1" > Mail/drafts/.mh_sequences
+
+dir=`pwd`
+echo 'quit' | compcmd -draftfolder drafts -use| sed "s|$dir/*||;s|  *$||"
+cat Mail/drafts/1
+],
+[0],
+[-- Editor invocation: Mail/drafts/1
+-- Input file:
+From: gray
+To: root
+Subject: test input
+
+message body
+-- Input file end
+What now? draft left on "Mail/drafts/1".
+From: gray
+To: root
+Subject: test input
+
+message body
+Seen by mhed
+])
+
+
 m4_popdef([compcmd])
 m4_popdef([MH_KEYWORDS])