once readable

- use once instead of on when listening for readable event
- closes #28

Author: doowb

lib/base.js

@@ -33,7 +33,7 @@ function copyBase(src, dest, options, callback) {
 
   var rs = fs.createReadStream(src)
     .on('error', handleError('read', src, opts, cb))
-    .on('readable', listener)
+    .once('readable', listener)
     .on('end', listener);
 
   function ws() {