TxBuilder: fix OP_0 in buildComplete

src/transaction_builder.js

@@ -242,11 +242,16 @@ TransactionBuilder.prototype.__build = function (allowIncomplete) {
           })
 
           // fill in blanks with OP_0
+          if (allowIncomplete) {
             for (var i = 0; i < msSignatures.length; ++i) {
               if (msSignatures[i]) continue
 
               msSignatures[i] = ops.OP_0
             }
+          } else {
+            // Array.prototype.filter returns non-sparse array
+            msSignatures = msSignatures.filter(function (x) { return x })
+          }
 
           var redeemScript = allowIncomplete ? undefined : input.redeemScript
           scriptSig = scripts.multisigInput(msSignatures, redeemScript)