Add writeFilter when in the readline

Switch \n with \r\n for all strings printed out.
Necessary for writev patch.

lib/readline.js

@@ -17,6 +17,20 @@ exports.createInterface = function (output, completer) {
   return new Interface(output, completer);
 };
 
+function writeFilter (stream) {
+  if (stream._writeFiltered) return;
+  stream._writeFiltered = true;
+  stream._normalWrite = stream.write;
+  stream.write = function (d) {
+    var args = Array.prototype.slice.call(arguments);
+    if (typeof d == 'string') {
+      args[0] = d.replace(/([^\r])\n|^\n/g, '$1\r\n');
+    }
+    // TODO what about buffers?
+    return stream._normalWrite.apply(stream, args);
+  }
+}
+
 function Interface (output, completer) {
   if (!(this instanceof Interface)) return new Interface(output, completer);
   EventEmitter.call(this);
@@ -35,6 +49,9 @@ function Interface (output, completer) {
   if (this.enabled) {
     // input refers to stdin
 
+    writeFilter(this.output);
+    writeFilter(process.stdout);
+
     // Current line
     this.line = "";
 
@@ -99,8 +116,6 @@ Interface.prototype._addHistory = function () {
 Interface.prototype._refreshLine  = function () {
   if (this._closed) return;
 
-  stdio.setRawMode(true);
-
   // Cursor to left edge.
   this.output.write('\x1b[0G');
 
@@ -288,8 +303,7 @@ Interface.prototype._ttyWrite = function (b) {
 
     case 13:    /* enter */
       var line = this._addHistory();
-      this.output.write('\n\x1b[0G');
-      stdio.setRawMode(false);
+      this.output.write('\r\n');
       this.emit('line', line);
       break;