imap4d: don't issue spurious unsolicited responses after EXPUNGE.

* imap4d/expunge.c (imap4d_expunge): Clear attribute table before
resynching.
* imap4d/imap4d.h (imap4d_sync_invalidate): New extern.
* imap4d/sync.c (invalidate_attr_table): Rename to imap4d_sync_invalidate;
make extern. All callers updated.

@@ -39,6 +39,7 @@ imap4d_expunge (struct imap4d_command *command, imap4d_tokbuf_t tok)
   /* FIXME: check for errors.  */
   mu_mailbox_expunge (mbox);
 
+  imap4d_sync_invalidate ();
   imap4d_sync ();
   return io_completion_response (command, RESP_OK, "Completed");
 }

@@ -324,6 +324,7 @@ int make_interdir (const char *name, int delim, int perms);
 
 /* Synchronisation on simultaneous access.  */
 extern int imap4d_sync (void);
+extern void imap4d_sync_invalidate (void);
 extern int imap4d_sync_flags (size_t);
 extern size_t uid_to_msgno (size_t);
 extern void imap4d_set_observer (mu_mailbox_t mbox);

@@ -39,8 +39,8 @@ realloc_attributes (size_t total)
   attr_table_count = total;
 }
 
-static void
-invalidate_attr_table ()
+void
+imap4d_sync_invalidate ()
 {
   attr_table_valid = 0;
   attr_table_count = 0;
@@ -191,7 +191,7 @@ imap4d_sync (void)
      It may be because of close or before select/examine a new mailbox.
      If it was a close we do not send any notification.  */
   if (mbox == NULL)
-    invalidate_attr_table ();
+    imap4d_sync_invalidate ();
   else if (!attr_table_valid || !mu_mailbox_is_updated (mbox))
     {
       if (mailbox_corrupt)
@@ -205,7 +205,7 @@ imap4d_sync (void)
 	  if (status)
 	    imap4d_bye (ERR_MAILBOX_CORRUPTED);
 	  imap4d_set_observer (mbox);
-	  invalidate_attr_table ();
+	  imap4d_sync_invalidate ();
 	  mailbox_corrupt = 0;
 	  io_untagged_response (RESP_NONE,
 		             "OK [ALERT] Mailbox modified by another program");