buffer: fix cyclic dependency with util

PR-URL: https://github.com/nodejs/io.js/pull/1988
Fixes: https://github.com/nodejs/io.js/issues/1987
Reviewed-By: Roman Reiss <me@silverwind.io>

lib/buffer.js

@@ -3,7 +3,6 @@
 
 const binding = process.binding('buffer');
 const smalloc = process.binding('smalloc');
-const util = require('util');
 const internalUtil = require('internal/util');
 const alloc = smalloc.alloc;
 const truncate = smalloc.truncate;
@@ -457,7 +456,7 @@ Buffer.prototype.fill = function fill(val, start, end) {
 
 
 // XXX remove in v0.13
-Buffer.prototype.get = util.deprecate(function get(offset) {
+Buffer.prototype.get = internalUtil.deprecate(function get(offset) {
   offset = ~~offset;
   if (offset < 0 || offset >= this.length)
     throw new RangeError('index out of range');
@@ -466,7 +465,7 @@ Buffer.prototype.get = util.deprecate(function get(offset) {
 
 
 // XXX remove in v0.13
-Buffer.prototype.set = util.deprecate(function set(offset, v) {
+Buffer.prototype.set = internalUtil.deprecate(function set(offset, v) {
   offset = ~~offset;
   if (offset < 0 || offset >= this.length)
     throw new RangeError('index out of range');

test/parallel/test-util.js

@@ -71,6 +71,10 @@ assert.equal(true, util.isPrimitive(Infinity));
 assert.equal(true, util.isPrimitive(NaN));
 assert.equal(true, util.isPrimitive(Symbol('symbol')));
 
+// isBuffer
+assert.equal(false, util.isBuffer('foo'));
+assert.equal(true, util.isBuffer(new Buffer('foo')));
+
 // _extend
 assert.deepEqual(util._extend({a:1}),             {a:1});
 assert.deepEqual(util._extend({a:1}, []),         {a:1});