From 6154b1f7a1c3215fc1ff5948ef2bad630c5e4e35 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Thu, 14 Jan 2016 01:16:39 -0800
Subject: [PATCH] improve tx verification.

---
 lib/bcoin/tx.js | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index 5a8b5aaf..2c996d94 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -689,13 +689,20 @@ TX.prototype.verify = function verify(index, force, flags) {
     if (!input.out.tx)
       return false;
 
-    output = input.out.tx.outputs[input.out.index];
-
-    assert(input.out.tx.outputs.length > input.out.index);
+    // Somethis is very wrong if this is
+    // not the case.
     assert.equal(input.out.tx.hash('hex'), input.out.hash);
 
-    // Transaction cannot reference itself
-    if (input.out.tx.hash('hex') === this.hash('hex'))
+    // Grab the previous output.
+    output = input.out.tx.outputs[input.out.index];
+
+    // Transaction is referencing an output
+    // that does not exist.
+    if (!output)
+      return false;
+
+    // Transaction cannot reference itself.
+    if (input.out.hash === this.hash('hex'))
       return false;
 
     return bcoin.script.verify(input.script, output.script, this, i, flags);