From 9fd3bbb827290c608a509f44af06d550fe631ac5 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sat, 16 Apr 2016 20:04:38 -0700
Subject: [PATCH] improve coin selection.

---
 lib/bcoin/mtx.js | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/lib/bcoin/mtx.js b/lib/bcoin/mtx.js
index 6c158ecb..f3a793ec 100644
--- a/lib/bcoin/mtx.js
+++ b/lib/bcoin/mtx.js
@@ -1075,12 +1075,6 @@ MTX.prototype.selectCoins = function selectCoins(coins, options) {
   // Null the inputs if there are any.
   tx.inputs.length = 0;
 
-  if (options.confirmed) {
-    coins = coins.filter(function(coin) {
-      return coin.height !== -1;
-    });
-  }
-
   if (!options.selection || options.selection === 'age') {
     // Oldest unspents first
     coins = coins.slice().sort(function(a, b) {
@@ -1106,12 +1100,24 @@ MTX.prototype.selectCoins = function selectCoins(coins, options) {
   }
 
   function addCoins() {
+    var coin;
+
     while (index < coins.length) {
+      coin = coins[index];
+
+      if (options.confirmed && coin.height === -1)
+        continue;
+
+      if (network.height !== -1 && coin.coinbase) {
+        if (network.height + 1 < coin.height + constants.tx.coinbaseMaturity)
+          continue;
+      }
+
       // Add new inputs until TX will have enough
       // funds to cover both minimum post cost
       // and fee.
-      tx.addInput(coins[index]);
-      chosen.push(coins[index]);
+      tx.addInput(coin);
+      chosen.push(coin);
       index++;
 
       if (options.selection === 'all')