buffer: Fix incorrect Buffer.compare behavior

Fixes #7551

Signed-off-by: Trevor Norris <trev.norris@gmail.com>

lib/buffer.js

@@ -135,7 +135,7 @@ Buffer.compare = function compare(a, b) {
       !(b instanceof Buffer))
     throw new TypeError('Arguments must be Buffers');
 
-  return internal.compare(b, a);
+  return internal.compare(a, b);
 };
 
 

test/simple/test-buffer.js

@@ -1048,10 +1048,10 @@ assert.equal(c.compare(d), 1);
 assert.equal(d.compare(b), 1);
 assert.equal(b.compare(d), -1);
 
-assert.equal(Buffer.compare(b, c), 1);
-assert.equal(Buffer.compare(c, d), -1);
-assert.equal(Buffer.compare(d, b), -1);
-assert.equal(Buffer.compare(b, d), 1);
+assert.equal(Buffer.compare(b, c), -1);
+assert.equal(Buffer.compare(c, d), 1);
+assert.equal(Buffer.compare(d, b), 1);
+assert.equal(Buffer.compare(b, d), -1);
 
 assert.throws(function() {
   var b = new Buffer(1);