improve tx building. minor style fixes. utils.uniq.

lib/bcoin/script.js

@@ -1021,6 +1021,8 @@ script.isMultisig = function isMultisig(s, pubs) {
 };
 
 script.isScripthash = function isScripthash(s, hash) {
+  var res;
+
   s = script.subscript(s);
 
   if (script.lockTime(s))
@@ -1029,7 +1031,7 @@ script.isScripthash = function isScripthash(s, hash) {
   if (s.length !== 3)
     return false;
 
-  var res = s[0] === 'hash160'
+  res = s[0] === 'hash160'
     && Array.isArray(s[1])
     && s[1].length === 20
     && s[2] === 'eq';

lib/bcoin/tx.js

@@ -64,6 +64,7 @@ function TX(data, block) {
   this.ps = this.ts === 0 ? +new Date() / 1000 : 0;
 
   this.changeAddress = data.changeAddress || null;
+  this.changeOutput = data.changeOutput || null;
 }
 
 TX.fee = 10000;
@@ -283,11 +284,13 @@ TX.prototype.signInput = function signInput(input, key, type) {
         break;
     }
 
+    // Public key is not in the prev_out script
     if (ki === keys.length)
-      throw new Error('Public key is not in the prev_out script');
+      return;
 
+    // No signature slot available
     if (ki + 1 > len - 1)
-      throw new Error('No signature slot available');
+      return;
 
     // Add our signature to the correct slot
     // and count the total number of signatures.
@@ -729,13 +732,15 @@ TX.prototype.utxos = function utxos(unspent) {
 TX.prototype.fillUnspent = function fillUnspent(unspent, changeAddress) {
   var result = unspent.utxos ? unspent : this.utxos(unspent);
 
-  this.changeAddress = changeAddress || this.changeAddress;
+  this.changeAddress = changeAddress
+    || this.changeAddress
+    || utxos[0].output.addr;
 
   if (!result)
     return result;
 
-  result.utxos.forEach(function(utxo) {
-    this.input(utxo, null);
+  result.utxos.forEach(function(input) {
+    this.input(input);
   }, this);
 
   if (result.change.cmpn(TX.dust) < 0) {
@@ -743,6 +748,8 @@ TX.prototype.fillUnspent = function fillUnspent(unspent, changeAddress) {
     assert(this.getFee().cmp(result.fee.add(result.change)) === 0);
     this.changeOutput = null;
   } else {
+    if (!this.changeAddress)
+      throw new Error('No change address');
     this.output({
       address: this.changeAddress,
       value: result.change

lib/bcoin/utils.js

@@ -798,3 +798,15 @@ utils.writeIntv = function writeIntv(arr, value, off) {
   utils.writeU64(arr, value, off + 1);
   return 9;
 };
+
+utils.uniq = function(obj) {
+  var out = [];
+  var i = 0;
+
+  for (; i < obj.length; i++) {
+    if (!~out.indexOf(obj[i]))
+      out.push(obj[i]);
+  }
+
+  return out;
+};

lib/bcoin/wallet.js

@@ -41,6 +41,7 @@ function Wallet(options, passphrase) {
   this.key = null;
   this.loaded = false;
   this.lastTs = 0;
+  this.changeAddress = options.changeAddress || null;
 
   if (options.priv instanceof bcoin.hd.priv) {
     this.hd = options.priv;
@@ -459,8 +460,9 @@ Wallet.prototype.scriptOutputs = function scriptOutputs(tx, options, outputs) {
   return outputs.length;
 };
 
-Wallet.prototype.fillUnspent = function fillUnspent(tx, change) {
-  return tx.fillUnspent(this.unspent(), change || this.getFullAddress());
+Wallet.prototype.fillUnspent = function fillUnspent(tx, changeAddress) {
+  changeAddress = changeAddress || this.changeAddress || this.getFullAddress();
+  return tx.fillUnspent(this.unspent(), changeAddress);
 };
 
 Wallet.prototype.scriptInputs = function scriptInputs(tx, inputs) {
@@ -544,12 +546,18 @@ Wallet.prototype.balance = function balance() {
   return this.tx.balance();
 };
 
-Wallet.prototype.fill = function fill(tx, cb) {
-  var result = tx.fillUnspent(this.unspent(), this.getAddress());
-  var err;
+Wallet.prototype.fill = function fill(tx, changeAddress, cb) {
+  var result, err;
+
+  if (typeof changeAddress === 'function') {
+    cb = changeAddress;
+    changeAddress = null;
+  }
 
   cb = utils.asyncify(cb);
 
+  result = this.fillUnspent(tx, changeAddress);
+
   if (!result) {
     err = new Error('Not enough funds');
     err.minBalance = tx.total;