Add SIGWINCH handler for readline

lib/readline.js

@@ -46,15 +46,21 @@ function Interface (output, completer) {
 
     this.history = [];
     this.historyIndex = -1;
+
+    exports.columns = process.binding('stdio').getColumns();
+
+    if (process.listeners("SIGWINCH").length === 0) {
+      process.on("SIGWINCH", function () {
+        exports.columns = process.binding('stdio').getColumns();
+      });
+    }
   }
 }
 
 inherits(Interface, EventEmitter);
 
 Interface.prototype.__defineGetter__("columns", function () {
-  if (this.enabled) {
+  return exports.columns;
-    return stdio.getColumns();
-  }
 });
 
 Interface.prototype.setPrompt = function (prompt, length) {