Connection: guard possible direct socket write

lib/Connection.js

@@ -1079,7 +1079,7 @@ Connection.prototype.__defineGetter__('seq', function() {
 });
 
 Connection.prototype._resUntagged = function(info) {
-  var type = info.type, i, len, box, attrs;
+  var type = info.type, i, len, box, attrs, key;
 
   if (type === 'bye')
     this._sock.end();
@@ -1148,7 +1148,7 @@ Connection.prototype._resUntagged = function(info) {
       if (!this._box)
         this._createCurrentBox();
 
-      var key = info.textCode.key.toUpperCase();
+      key = info.textCode.key.toUpperCase();
 
       if (key === 'UIDVALIDITY')
         this._box.uidvalidity = info.textCode.val;
@@ -1238,7 +1238,7 @@ Connection.prototype._resUntagged = function(info) {
       var msg = this._curReq.fetchCache[info.num],
           keys = Object.keys(info.text),
           keyslen = keys.length,
-          toget, msgEmitter, j, key;
+          toget, msgEmitter, j;
 
       if (msg === undefined) {
         // simple case -- no bodies were streamed
@@ -1564,7 +1564,10 @@ Connection.prototype._enqueue = function(fullcmd, promote, cb) {
     // defer until next tick for requests like APPEND and FETCH where access to
     // the request object is needed immediately after enqueueing
     process.nextTick(function() { self._processQueue(); });
-  } else if (this._curReq && this._curReq.type === 'IDLE') {
+  } else if (this._curReq
+             && this._curReq.type === 'IDLE'
+             && this._sock
+             && this._sock.writable) {
     this._idle.enabled = false;
     this.debug && this.debug('=> DONE');
     this._sock.write('DONE' + CRLF);