Add readOnly attribute to mailbox object when opening

README.md

@@ -194,6 +194,7 @@ node-imap exposes one object: **ImapConnection**.
 
 * _Box_ is an object representing the currently open mailbox, and has the following properties:
     * **name** - <_string_> - The name of this mailbox.
+    * **readOnly** - <_boolean_> - True if this mailbox was opened in read-only mode.
     * **validity** - <_string_> - A number that can be used to determine if UIDs in this mailbox have changed since the last time this mailbox was opened.
     * **permFlags** - <_array_> - A list of flags that can be permanently added/removed to/from messages in this mailbox.
     * **messages** - <_object_> Contains various message counts for this mailbox:

lib/imap.js

@@ -536,6 +536,7 @@ ImapConnection.prototype.connect = function(loginCb) {
       if (state.status === STATES.BOXSELECTING) {
         if (/^A\d+ OK/i.test(line)) {
           sendBox = true;
+          state.box.readOnly = (requests[0].cmd === 'EXAMINE');
           state.status = STATES.BOXSELECTED;
         } else {
           state.status = STATES.AUTH;