ensures that pubKey length is greater than m

ensure that pubKey length is greater than m

use Array.isArray over instanceof

error message

src/script.js

@@ -304,6 +304,8 @@ Script.createP2SHScriptPubKey = function(hash) {
 
 // m [pubKeys ...] n OP_CHECKMULTISIG
 Script.createMultisigScriptPubKey = function(m, pubKeys) {
+  assert(Array.isArray(pubKeys), 'Expected Array, got: ' + pubKeys)
+  assert(pubKeys.length >= m, 'Not enough pubKeys provided')
   var script = new Script()
   var n = pubKeys.length
 

test/script.js

@@ -120,6 +120,10 @@ describe('Script', function() {
 
       assert.equal(multisigAddress.toString(), '32vYjxBb7pHJJyXgNk8UoK3BdRDxBzny2v')
     })
+
+    it('should throw on not enough pubKeys provided', function() {
+        assert.throws(function() {Script.createMultisigScriptPubKey(4, pubKeys)},  /Not enough pubKeys provided/)
+    })
   })
 
   describe('2-of-2 Multisig scriptSig', function() {