Reorganize error codes.

* libmailutils/diag/errors (MU_ERR_TCP_NO_HOST)
(MU_ERR_TCP_NO_PORT): Change wording.
(MU_ERR_UNSAFE_PERMS): Remove error code.
(MU_ERR_NO_HANDLER): Remove. All uses replaced by ENOSYS.
(MU_ERR_OUT_NULL): Remove. MU_ERR_OUT_PTR_NULL is used instead.
(MU_ERR_MBX_NULL): Remove. Use EINVAL instead.
(MU_ERR_BAD_822_FORMAT): Rename to MU_ERR_INVALID_EMAIL. Change wording.
(MU_ERR_REPLY): Change wording.

* libmailutils/url/create.c: Remove misguiding comments
* libmailutils/url/set-service.c: Likewise.

* libmailutils/mailbox/mailbox.c (mu_mailbox_open): Return EACCES
if trying to update quick-access mailboxes.
(mu_mailbox_get_stream): Mark for deletion.
* libmailutils/stream/fltstream.c (filter_read)
(filter_write_internal): Return MU_ERR_BUFSPACE if requested more
space than available in I/O buffers.
* libproto/mbox/mbox.c (mbox_expunge_unlocked): Send MU_EVT_MAILBOX_CORRUPT
event if the mailbox shrunk.
* libproto/mbox/mboxscan.c (mbox_scan_internal): Return MU_ERR_NOENT if
unable to locate message in quick-access mode.

@@ -97,7 +97,7 @@ actually help.
 #endif
 
 #define EOK	0
-#define EPARSE	MU_ERR_BAD_822_FORMAT
+#define EPARSE	MU_ERR_INVALID_EMAIL
 
 /*
  * Some convenience functions for dealing with dynamically re-sized

@@ -409,7 +409,7 @@ amd_init_mailbox (mu_mailbox_t mailbox, size_t amd_size,
   struct _amd_data *amd;
 
   if (mailbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (amd_size < sizeof (*amd))
     return EINVAL;
 
@@ -533,7 +533,7 @@ amd_close (mu_mailbox_t mailbox)
   int i;
     
   if (!mailbox)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
 
   amd = mailbox->data;
   
@@ -1018,9 +1018,7 @@ amd_append_message (mu_mailbox_t mailbox, mu_message_t msg)
   struct _amd_data *amd = mailbox->data;
   struct _amd_message *mhm;
 
-  if (!mailbox)
-    return MU_ERR_MBX_NULL;
-  if (!msg)
+  if (!mailbox || !msg)
     return EINVAL;
 
   mhm = calloc (1, amd->msg_size);

-
 # Error messages for GNU Mailutils
 # Copyright (C) 2005, 2006, 2007, 2010, 2011 Free Software Foundation,
 # Inc.
@@ -19,20 +18,20 @@
 MU_ERR_FAILURE              _("Operation failed")
 MU_ERR_CANCELED             _("Operation canceled")
 
-MU_ERR_NO_HANDLER           _("No registered handler")
 MU_ERR_EMPTY_VFN            _("Empty virtual function")
 
-MU_ERR_OUT_NULL             _("Pointer to output null")
-MU_ERR_OUT_PTR_NULL         _("Pointer to output pointer null")
+# A counterpart of EINVAL.  Functions receiving invalid input arguments
+# return EINVAL, those receiving invalid output arguments return this
+# code:
+MU_ERR_OUT_PTR_NULL         _("Null output pointer")
 
-MU_ERR_MBX_NULL             _("Mailbox null")
 MU_ERR_MBX_REMOVED          _("Mailbox removed")
 
 MU_ERR_NOT_OPEN             _("Resource not open")
 MU_ERR_OPEN                 _("Resource is already open")
 
-MU_ERR_BAD_822_FORMAT       _("Format of RFC822 object is bad")
-MU_ERR_EMPTY_ADDRESS        _("Address contains no addr specs")
+MU_ERR_INVALID_EMAIL        _("Malformed email address")
+MU_ERR_EMPTY_ADDRESS        _("Empty address list")
 
 MU_ERR_LOCKER_NULL          _("Locker null")
 MU_ERR_LOCK_CONFLICT        _("Conflict with previous locker")
@@ -47,13 +46,14 @@ MU_ERR_NO_SUCH_USER         _("No such user name")
 
 MU_ERR_GETHOSTBYNAME        _("DNS name resolution failed")
 MU_ERR_BAD_RESUMPTION       _("State busy must resume operation")
-MU_ERR_MAILER_BAD_FROM      _("Not a valid mailer from address")
-MU_ERR_MAILER_BAD_TO        _("Not a valid mailer to address")
-MU_ERR_MAILER_NO_RCPT_TO    _("No receipt addresses found")
+MU_ERR_MAILER_BAD_FROM      _("Not a valid sender address")
+MU_ERR_MAILER_BAD_TO        _("Not a valid recipient address")
+MU_ERR_MAILER_NO_RCPT_TO    _("No recipient addresses found")
 MU_ERR_MAILER_BAD_URL       _("Malformed or unsupported mailer URL")
-MU_ERR_SMTP_RCPT_FAILED     _("SMTP rcpt to command failed")
-MU_ERR_TCP_NO_HOST          _("Tcp connections need a host")
-MU_ERR_TCP_NO_PORT          _("Tcp connections need a positive port")
+MU_ERR_SMTP_RCPT_FAILED     _("SMTP RCPT command failed")
+
+MU_ERR_TCP_NO_HOST          _("Required host specification is missing")
+MU_ERR_TCP_NO_PORT          _("Invalid port or service specification")
 
 MU_ERR_BAD_2047_INPUT       _("Input string is not RFC 2047 encoded")
 MU_ERR_BAD_2047_ENCODING    _("Not a valid RFC 2047 encoding")
@@ -63,7 +63,7 @@ MU_ERR_NOPASSWORD           _("User password is not supplied")
 MU_ERR_BADREPLY             _("Invalid reply from the remote host")
 
 MU_ERR_SEQ                  _("Bad command sequence")
-MU_ERR_REPLY                _("Erroneous reply received")
+MU_ERR_REPLY                _("Operation rejected by remote party")
 
 MU_ERR_BAD_AUTH_SCHEME      _("Unsupported authentication scheme")
 MU_ERR_AUTH_FAILURE         _("Authentication failed")
@@ -78,6 +78,7 @@ MU_ERR_NOENT                _("Requested item not found")
 MU_ERR_EXISTS               _("Item already exists")
 MU_ERR_BUFSPACE             _("Not enough buffer space")
 
+# Database errors
 MU_ERR_SQL                  _("SQL error")
 MU_ERR_DB_ALREADY_CONNECTED _("Already connected to the database")
 MU_ERR_DB_NOT_CONNECTED     _("Not connected to the database")
@@ -94,9 +95,15 @@ MU_ERR_READ                 _("Read error")
 MU_ERR_NO_TRANSPORT         _("Transport stream not set")
 MU_ERR_AUTH_NO_CRED         _("No credentials supplied")
 
+# URL-related errors
 MU_ERR_URL_MISS_PARTS       _("URL missing required parts")
 MU_ERR_URL_EXTRA_PARTS      _("URL has parts not allowed by its scheme")
+MU_ERR_URL_INVALID_PARAMETER _("Invalid parameter in URL")
 
+# This error is returned when the requested data cannot be obtained right
+# now or by the given means, or obtaining them is too costly, e.g. as
+# obtaining number of lines in a message via POP3 (which would involve
+# downloading entire message) by mu_message_quick_lines.
 MU_ERR_INFO_UNAVAILABLE	    _("Information is not yet available")
 
 # The following are mapped to the corresponding EAI_ errors
@@ -106,7 +113,7 @@ MU_ERR_SOCKTYPE             _("Socket type not supported")
 MU_ERR_FAMILY               _("Address family not supported")
 MU_ERR_SERVICE              _("Requested service not supported")
 
-# File safety check
+# File safety checks
 MU_ERR_PERM_OWNER_MISMATCH  _("File owner mismatch")
 MU_ERR_PERM_GROUP_WRITABLE  _("Group writable file")
 MU_ERR_PERM_WORLD_WRITABLE  _("World writable file")
@@ -116,5 +123,3 @@ MU_ERR_PERM_LINKED_WRDIR    _("Linked file in a writable directory")
 MU_ERR_PERM_DIR_IWGRP       _("File in group writable directory")
 MU_ERR_PERM_DIR_IWOTH       _("File in world writable directory")
 
-# A simpler version of the above.  Possibly will be removed in the future.
-MU_ERR_UNSAFE_PERMS         _("Unsafe file permissions")

@@ -145,7 +145,7 @@ _mailbox_create_from_record (mu_mailbox_t *pmbox,
 	*pmbox = mbox;
       return status;
     }
-  return MU_ERR_NO_HANDLER;
+  return ENOSYS;
 }
 
 static int
@@ -156,7 +156,7 @@ _create_mailbox0 (mu_mailbox_t *pmbox, mu_url_t url, const char *name)
   if (mu_registrar_lookup_url (url, MU_FOLDER_ATTRIBUTE_FILE, &record, NULL)
       == 0)
     return _mailbox_create_from_record (pmbox, record, url, name);
-  return MU_ERR_NO_HANDLER;
+  return ENOSYS;
 }
 
 static int
@@ -268,7 +268,7 @@ mu_mailbox_open (mu_mailbox_t mbox, int flag)
   int rc;
   
   if (!mbox)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (mbox->_open == NULL)
     return MU_ERR_EMPTY_VFN;
   if (mbox->flags & _MU_MAILBOX_OPEN)
@@ -278,7 +278,7 @@ mu_mailbox_open (mu_mailbox_t mbox, int flag)
       /* Quick access mailboxes are read-only */
       if (flag & (MU_STREAM_WRITE 
 		  | MU_STREAM_APPEND | MU_STREAM_CREAT))
-	return EINVAL; /* FIXME: Better error code, please? */
+	return EACCES;
     }
   rc = mbox->_open (mbox, flag);
   if (rc == 0)
@@ -292,7 +292,7 @@ mu_mailbox_close (mu_mailbox_t mbox)
   int rc;
 
   if (!mbox)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (!(mbox->flags & _MU_MAILBOX_OPEN))
     return MU_ERR_NOT_OPEN;
   if (mbox == NULL || mbox->_close == NULL)
@@ -308,7 +308,7 @@ int
 mu_mailbox_remove (mu_mailbox_t mbox)
 {
   if (!mbox)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (mbox->flags & _MU_MAILBOX_OPEN)
     return MU_ERR_OPEN;
   if (mbox->flags & _MU_MAILBOX_REMOVED)
@@ -325,7 +325,7 @@ mu_mailbox_flush (mu_mailbox_t mbox, int expunge)
   int status = 0;
   
   if (!mbox)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (mbox->flags & _MU_MAILBOX_REMOVED)
     return MU_ERR_MBX_REMOVED;
   if (!(mbox->flags & _MU_MAILBOX_OPEN))
@@ -354,7 +354,7 @@ mu_mailbox_flush (mu_mailbox_t mbox, int expunge)
 
 #define _MBOX_CHECK_FLAGS(mbox)			\
   if (mbox == NULL)				\
-    return MU_ERR_MBX_NULL;			\
+    return EINVAL;			        \
   if (mbox->flags & _MU_MAILBOX_REMOVED)	\
     return MU_ERR_MBX_REMOVED;			\
   if (!(mbox->flags & _MU_MAILBOX_OPEN))	\
@@ -517,7 +517,7 @@ int
 mu_mailbox_set_locker (mu_mailbox_t mbox, mu_locker_t locker)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (mbox->locker)
     mu_locker_destroy (&mbox->locker);
   mbox->locker = locker;
@@ -528,7 +528,7 @@ int
 mu_mailbox_get_locker (mu_mailbox_t mbox, mu_locker_t *plocker)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (plocker == NULL)
     return MU_ERR_OUT_PTR_NULL;
   *plocker = mbox->locker;
@@ -539,9 +539,9 @@ int
 mu_mailbox_get_flags (mu_mailbox_t mbox, int *flags)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
-  if (!*flags)
-    return MU_ERR_OUT_NULL;
+    return EINVAL;
+  if (!flags)
+    return MU_ERR_OUT_PTR_NULL;
   *flags = mbox->flags & ~_MU_MAILBOX_MASK;
   return 0;
 }
@@ -550,7 +550,7 @@ int
 mu_mailbox_set_stream (mu_mailbox_t mbox, mu_stream_t stream)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (mbox->flags & MU_STREAM_QACCESS)
     return MU_ERR_BADOP;
   if (mbox->stream)
@@ -560,19 +560,20 @@ mu_mailbox_set_stream (mu_mailbox_t mbox, mu_stream_t stream)
 }
 
 /* FIXME: This is a problem.  We provide a mu_mailbox_get_stream ()
-   and this stream is special it should, in theory, represent
-   a "view" of a flow of messages.  But providing this perspective
-   may make sense for local mailboxes but downright impossible
-   for a remote mailbox, short on downloading the entire mailbox
+   and this stream is special: it should, in theory, represent
+   a "view" of a flow of messages.  However, providing this perspective
+   may make sense for local mailboxes, but downright impossible
+   for remote mailboxes, short on downloading entire mailbox
    locally.
-   The question is : should this function be removed?
-   So far it as been used on local mailboxes to get offsets.  */
+
+   This function will be removed in the short run.  It is no longer
+   used by MU.  */
 int
 mu_mailbox_get_stream (mu_mailbox_t mbox, mu_stream_t *pstream)
 {
   /* FIXME: Deprecation warning */
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (pstream == NULL)
     return MU_ERR_OUT_PTR_NULL;
 
@@ -592,7 +593,7 @@ int
 mu_mailbox_get_streamref (mu_mailbox_t mbox, mu_stream_t *pstream)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (pstream == NULL)
     return MU_ERR_OUT_PTR_NULL;
 
@@ -611,7 +612,7 @@ int
 mu_mailbox_get_observable (mu_mailbox_t mbox, mu_observable_t *pobservable)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (pobservable == NULL)
     return MU_ERR_OUT_PTR_NULL;
 
@@ -629,7 +630,7 @@ int
 mu_mailbox_set_property (mu_mailbox_t mbox, mu_property_t property)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (mbox->property)
     mu_property_unref (mbox->property);
   mbox->property = property;
@@ -641,7 +642,7 @@ int
 mu_mailbox_get_property (mu_mailbox_t mbox, mu_property_t *pproperty)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (pproperty == NULL)
     return MU_ERR_OUT_PTR_NULL;
   
@@ -665,7 +666,7 @@ int
 mu_mailbox_get_url (mu_mailbox_t mbox, mu_url_t *purl)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (purl == NULL)
     return MU_ERR_OUT_PTR_NULL;
   *purl = mbox->url;
@@ -676,7 +677,7 @@ int
 mu_mailbox_get_folder (mu_mailbox_t mbox, mu_folder_t *pfolder)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (pfolder == NULL)
     return MU_ERR_OUT_PTR_NULL;
   *pfolder = mbox->folder;
@@ -687,7 +688,7 @@ int
 mu_mailbox_set_folder (mu_mailbox_t mbox, mu_folder_t folder)
 {
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
    mbox->folder = folder;
   return 0;
 }
@@ -715,9 +716,9 @@ mu_mailbox_get_uidls (mu_mailbox_t mbox, mu_list_t *plist)
   int status;
 
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
-  if (plist == NULL)
     return EINVAL;
+  if (plist == NULL)
+    return MU_ERR_OUT_PTR_NULL;
   status = mu_list_create (&list);
   if (status)
     return status;
@@ -847,9 +848,9 @@ mu_mailbox_translate (mu_mailbox_t mbox, int cmd, size_t from, size_t *to)
   mu_message_t msg;
   
   if (mbox == NULL)
-    return MU_ERR_MBX_NULL;
-  if (to == NULL)
     return EINVAL;
+  if (to == NULL)
+    return MU_ERR_OUT_PTR_NULL;
   if (mbox->flags & MU_STREAM_QACCESS)
     return MU_ERR_BADOP;
 

@@ -372,7 +372,7 @@ safe_address_create (mu_address_t *paddr, const char *addr_str,
 		     const char *who)
 {
   int status = mu_address_create (paddr, addr_str);
-  if (status == MU_ERR_BAD_822_FORMAT)
+  if (status == MU_ERR_INVALID_EMAIL)
     {
       int rc;
       char *p;
@@ -394,7 +394,7 @@ safe_address_create (mu_address_t *paddr, const char *addr_str,
 	  rc = mu_address_create (paddr, p);
 	  if (rc == 0)
 	    status = 0;
-	  else if (rc == MU_ERR_BAD_822_FORMAT)
+	  else if (rc == MU_ERR_INVALID_EMAIL)
 	    mu_debug (MU_DEBCAT_MAILER, MU_DEBUG_TRACE1,
 		      ("%s address guess failed", who));
 	  else

@@ -197,7 +197,7 @@ filter_read (mu_stream_t stream, char *buf, size_t size, size_t *pret)
       
 	  if (iobuf.isize > MFB_RDBYTES (fs->inbuf)
 	      || iobuf.osize > MFB_FREESIZE (fs->outbuf))
-	    return MU_ERR_FAILURE; /* FIXME: special error code? */
+	    return MU_ERR_BUFSPACE;
 	  
 	  /* iobuf.osize contains number of bytes written to output */
 	  MFB_advance_level (&fs->outbuf, iobuf.osize);
@@ -334,7 +334,7 @@ filter_write_internal (mu_stream_t stream, enum mu_filter_command cmd,
       
       if (iobuf.isize > MFB_RDBYTES (fs->inbuf)
 	  || iobuf.osize > MFB_FREESIZE (fs->outbuf))
-	return MU_ERR_FAILURE; /* FIXME: special error code? */
+	return MU_ERR_BUFSPACE;
       
       /* iobuf.osize contains number of bytes written to output */
       MFB_advance_level (&fs->outbuf, iobuf.osize);

@@ -230,7 +230,7 @@ _message_open (mu_stream_t stream)
 		  offset += len;
 		  continue;
 		}
-	      return MU_ERR_BAD_822_FORMAT;
+	      return MU_ERR_INVALID_EMAIL;
 	    }
 	  has_headers = 1;
 	  if (!env_from || !env_date)

@@ -34,7 +34,7 @@ AT_CLEANUP
 TESTADDR([Sam <@[matrix (smtp)], @[nexus: [node 12]]:sroberts@[10].[1]>],[],
 [1],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR([a@b,z@y],[],
@@ -226,7 +226,7 @@ TESTADDR([a group: ,, ;],[group],
 TESTADDR([Sam <@[matrix (smtp)], @[nexus: [node 12]]:sroberts@[10].[1]> ;],[],
 [1],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR([Aliens: Sam <@[matrix (smtp)]: sam@sam>, sroberts@[10].[1];],[],
@@ -296,7 +296,7 @@ route <@mail2.uniserve.com>
 TESTADDR([< (hey) @ (hey, )smtp1.sympatico.ca, mail2.uniserve.com (hoo!):sroberts@uniserve.com>],[],
 [1],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR([hw@570.com (Hardware Support Account)],[],
@@ -374,7 +374,7 @@ local-part <paul> domain <pitbull-productions.com>
 TESTADDR(["'sam@cogent.ca'" <sam@cogent.ca>, "'sroberts@uniserve.com'"],[],
 [0],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR(["'sroberts\@certicom\.ca'" <sroberts@certicom.ca>],[],
@@ -603,7 +603,7 @@ local-part <zwk%f36.n480.z2.fidonet.org> domain <f36.n480.z2.fidonet.org>
 TESTADDR(['Dan Dall'Acqua' <ddallacqua@noetic.ab.ca>, 'Dave Shyong'],[],
 [0],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR([0xdeadbeef-request@petting-zoo.net],[],
@@ -657,7 +657,7 @@ local-part <Nick_Shelness> domain <motorcity2.lotus.com>
 TESTADDR([<all: >],[],
 [1],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR([<fyi-admin@emyr.net>],[],
@@ -1008,7 +1008,7 @@ local-part <Kieran.O'Leary> domain <anpost.ie>
 TESTADDR([rfunk@wks.uts.ohio-state.eduofflinemailer-bounce@dikke.penguin.nl],[],
 [1],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR([root],[],
@@ -1021,7 +1021,7 @@ local-part <root> domain <localhost>
 TESTADDR([whom it may concern: ;;whom.it.may.concern: ;],[],
 [1],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 TESTADDR([whom it may concern: mutt-dev@mutt.org, mutt-users@mutt.org;],[],
@@ -1052,7 +1052,7 @@ local-part <bach> domain <somewhere.org>
 TESTADDR(["A bad quote\" <devnull@localhost>],[],
 [1],
 [],
-[MU_ERR_BAD_822_FORMAT
+[MU_ERR_INVALID_EMAIL
 ])
 
 

@@ -476,7 +476,7 @@ _mu_url_create_internal (struct mu_url_ctx *ctx, mu_url_t hint)
 	      /* FIXME: Another proto? */
 	      struct servent *sp = getservbyname (url->portstr, "tcp");
 	      if (!sp)
-		return MU_ERR_TCP_NO_PORT; //FIXME: Error code?
+		return MU_ERR_TCP_NO_PORT; 
 	      url->port = ntohs (sp->s_port);
 	    }
 	  else

@@ -53,7 +53,7 @@ mu_url_set_service (mu_url_t url, const char *str)
 	  /* FIXME: 2. Another proto? */
 	  struct servent *sp = getservbyname (str, "tcp");
 	  if (!sp)
-	    return MU_ERR_TCP_NO_PORT; /*FIXME: Error code?*/
+	    return MU_ERR_TCP_NO_PORT;
 	  port = ntohs (sp->s_port);
 	}
       else if (n > USHRT_MAX)

@@ -204,7 +204,7 @@ mu_dbm_create_from_url (mu_url_t url, mu_dbm_file_t *db)
 		    }
 		}
 	      else if (name[5])
-		return MU_ERR_URL_EXTRA_PARTS;//FIXME: better error code
+		return MU_ERR_URL_INVALID_PARAMETER;
 	    }
 	  else if (strcmp (name, "none") == 0)
 	    {
@@ -221,7 +221,7 @@ mu_dbm_create_from_url (mu_url_t url, mu_dbm_file_t *db)
 	      val = DEFAULT_DBM_SAFETY_FLAGS;
 	    }
 	  else if (mu_file_safety_name_to_code (name, &val))
-	    return MU_ERR_URL_EXTRA_PARTS;//FIXME: better error code
+	    return MU_ERR_URL_INVALID_PARAMETER;
 
 	  if (negate)
 	    safety_flags &= ~val;

@@ -128,7 +128,7 @@ _mailbox_imap_and_imaps_init (mu_mailbox_t mailbox, int imaps)
   m_imap_t m_imap;
 
   if (!mailbox)
-    return MU_ERR_MBX_NULL;
+    return EINVAL;
   if (mailbox->folder == NULL)
     return EINVAL;
   

@@ -166,7 +166,7 @@ sendmail_send_message (mu_mailer_t mailer, mu_message_t msg, mu_address_t from,
 	  mu_debug (MU_DEBCAT_MAILER, MU_DEBUG_TRACE,
 		    ("envelope from (%s) not fully qualifed\n",
 		     emailfrom));
-	  return MU_ERR_BAD_822_FORMAT;
+	  return MU_ERR_INVALID_EMAIL;
 	}
 
       argc += 2;		/* -f from */
@@ -239,7 +239,7 @@ sendmail_send_message (mu_mailer_t mailer, mu_message_t msg, mu_address_t from,
 			("envelope to (%s) not fully qualifed",
 			 email));
 	      free (argvec);
-	      return MU_ERR_BAD_822_FORMAT;
+	      return MU_ERR_INVALID_EMAIL;
 	    }
 	  argvec[argc++] = email;
 	}

@@ -1307,6 +1307,8 @@ mbox_expunge_unlocked (mu_mailbox_t mailbox, size_t dirty, int remove_deleted,
       else if (size < mud->size)
 	{
 	  /* Corrupted mailbox. */
+	  mu_observable_notify (mailbox->observable, MU_EVT_MAILBOX_CORRUPT,
+				mailbox);
 	  mu_error (_("%s:%d: mailbox shrunk while expunging"),
 		    __FILE__, __LINE__);
 	  return MU_ERR_FAILURE; /* FIXME: need an error code for that */

@@ -346,7 +346,7 @@ mbox_scan_internal (mu_mailbox_t mailbox, mbox_message_t mum,
 	{
 	  /* In one-message mode, the positioning should be exact. */
 	  if (!isfrom)
-	    return EINVAL; /* FIXME: Better error code, please? */
+	    return MU_ERR_NOENT;
 	}
       
       /* Which part of the message are we in ?  */

@@ -34,7 +34,7 @@ mu_pop3_list (mu_pop3_t pop3, unsigned int msgno, size_t *psize)
   if (pop3 == NULL || msgno == 0)
     return EINVAL;
   if (psize == NULL)
-    return MU_ERR_OUT_NULL;
+    return MU_ERR_OUT_PTR_NULL;
 
   switch (pop3->state)
     {

@@ -53,7 +53,7 @@ MU_ERR_EMPTY_VFN = (MU_ERR_BASE+3)
 MU_ERR_OUT_NULL = (MU_ERR_BASE+4)
 MU_ERR_OUT_PTR_NULL = (MU_ERR_BASE+5)
 MU_ERR_MBX_NULL = (MU_ERR_BASE+6)
-MU_ERR_BAD_822_FORMAT = (MU_ERR_BASE+7)
+MU_ERR_INVALID_EMAIL = (MU_ERR_BASE+7)
 MU_ERR_EMPTY_ADDRESS = (MU_ERR_BASE+8)
 MU_ERR_LOCKER_NULL = (MU_ERR_BASE+9)
 MU_ERR_LOCK_CONFLICT = (MU_ERR_BASE+10)