From 397e1f7d0bf4ab56c9fb2e961738fa3ed2c22ec1 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 18 Apr 2016 21:37:27 -0700
Subject: [PATCH] more accurate removeData.

---
 lib/bcoin/chain.js  | 17 ++++++++-----
 lib/bcoin/script.js | 61 ++++++++++++++++++++++++++++++++++++++++++++-
 lib/bcoin/utils.js  | 22 ++++++++++++++++
 3 files changed, 93 insertions(+), 7 deletions(-)

diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 671e1062..32f515a8 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -850,17 +850,22 @@ Chain.prototype._checkInputs = function _checkInputs(block, prev, flags, callbac
             100));
         }
 
-        //if (self.options.verifySync !== true)
-        //  continue;
+        if (self.options.verifyAsync)
+          continue;
 
         if (!scriptCheck)
           continue;
 
         // Verify the scripts
         if (!tx.verify(j, true, flags)) {
-          utils.print(tx.rhash);
-          console.error(tx.inputs[j]);
-          //assert(!historical, 'BUG: Invalid inputs in historical data!');
+          bcoin.debug(
+            'Transaction failed consensus verification: %s',
+            tx.rhash);
+          bcoin.debug('TX:');
+          bcoin.debug(tx);
+          bcoin.debug('Input:');
+          bcoin.debug(tx.inputs[j]);
+          assert(!historical, 'BUG: Invalid inputs in historical data!');
           return callback(new VerifyError(block,
             'invalid',
             'mandatory-script-verify-flag-failed',
@@ -879,7 +884,7 @@ Chain.prototype._checkInputs = function _checkInputs(block, prev, flags, callbac
     if (block.getClaimed().cmp(block.getReward()) > 0)
       return callback(new VerifyError(block, 'invalid', 'bad-cb-amount', 100));
 
-    //if (self.options.verifySync === true)
+    if (!self.options.verifyAsync)
       return callback();
 
     if (!scriptCheck)
diff --git a/lib/bcoin/script.js b/lib/bcoin/script.js
index 04ca3b0e..1c2b2fa7 100644
--- a/lib/bcoin/script.js
+++ b/lib/bcoin/script.js
@@ -1869,24 +1869,83 @@ Script.array = function(value) {
 /**
  * Remove all matched data elements from
  * a script's code (used to remove signatures
- * before verification).
+ * before verification). Note that this
+ * compares and removes data on the _byte level_.
+ * It also reserializes the data to a single
+ * script with minimaldata encoding beforehand.
+ * A signature will _not_ be removed if it is
+ * not minimaldata.
+ * @see https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2014-November/006878.html
+ * @see https://test.webbtc.com/tx/19aa42fee0fa57c45d3b16488198b27caaacc4ff5794510d0c17f173f05587ff
  * @param {Buffer} data - Data element to match against.
  * @returns {Number} Total.
  */
 
 Script.prototype.removeData = function removeData(data) {
+  var total = 0;
+  var sig, raw, i, a, b;
+
+  if (!this.raw)
+    return this.removeDataFast(data);
+
+  sig = new Script([data]).encode();
+  raw = this.encode();
+
+  // Note that this is _faster_ than Buffer#indexOf.
+  for (i = 0; i < raw.length; i++) {
+    if (raw.length - i < sig.length)
+      break;
+    if (this._cmp(raw, sig, i) === 0) {
+      a = raw.slice(0, i);
+      b = raw.slice(i + sig.length);
+      raw = Buffer.concat([a, b]);
+      total++;
+    }
+  }
+
+  this.raw = raw;
+
+  return total;
+};
+
+Script.prototype._cmp = function _cmp(target, data, start) {
+  var i, a, b;
+
+  if (target.length - start < data.length)
+    return -1;
+
+  for (i = 0; i < data.length; i++) {
+    a = target[i + start];
+    b = data[i];
+    if (a < b)
+      return -1;
+    if (a > b)
+      return 1;
+  }
+
+  return 0;
+};
+
+Script.prototype.removeDataFast = function removeData(data) {
   var total = 0;
   var i;
 
   for (i = this.code.length - 1; i >= 0; i--) {
     if (!Buffer.isBuffer(this.code[i]))
       continue;
+    if (!Script.checkMinimal(this.code[i]))
+      continue;
     if (utils.equals(this.code[i], data)) {
       this.code.splice(i, 1);
       total++;
     }
   }
 
+  if (this.raw && total > 0) {
+    this.raw = null;
+    this.encode();
+  }
+
   return total;
 };
 
diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index 8afee663..d74906e5 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -997,6 +997,28 @@ utils.print = function print() {
   process.stdout.write(msg);
 };
 
+/**
+ * Write a message to stderr (console in browser).
+ * @param {Object|String} obj
+ * @param {...String} args
+ */
+
+utils.error = function error() {
+  var args = Array.prototype.slice.call(arguments);
+  var msg;
+
+  if (utils.isBrowser) {
+    msg = typeof args[0] === 'object'
+      ? args[0]
+      : utils.format(args, false).slice(0, -1);
+    console.error(msg);
+    return;
+  }
+
+  msg = utils.format(args, true);
+  process.stderr.write(msg);
+};
+
 /**
  * Shallow merge between multiple objects.
  * @param {Object} target