From 91acf2a607a69ef26c46ab12091e31e7d1866ae4 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Wed, 20 Apr 2016 09:01:10 -0700
Subject: [PATCH] new script decoder.

---
 lib/bcoin/script.js | 116 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

diff --git a/lib/bcoin/script.js b/lib/bcoin/script.js
index 0d334eeb..b533088e 100644
--- a/lib/bcoin/script.js
+++ b/lib/bcoin/script.js
@@ -12,6 +12,7 @@ var constants = bcoin.protocol.constants;
 var utils = require('./utils');
 var assert = utils.assert;
 var BufferWriter = require('./writer');
+var BufferReader = require('./reader');
 var opcodes = constants.opcodes;
 var STACK_TRUE = new Buffer([1]);
 var STACK_FALSE = new Buffer([]);
@@ -2154,6 +2155,8 @@ Script.isCode = function isCode(buf) {
     op = code[i];
     if (Buffer.isBuffer(op))
       continue;
+    if (op >= opcodes.OP_PUSHDATA1 && op <= opcodes.OP_PUSHDATA4)
+      return false;
     if (constants.opcodesByVal[op] == null)
       return false;
   }
@@ -2666,6 +2669,8 @@ Script.prototype.isNulldata = function isNulldata() {
     }
     if (op > opcodes.OP_16)
       return false;
+    if (op >= opcodes.OP_PUSHDATA1 && op <= opcodes.OP_PUSHDATA4)
+      return false;
   }
 
   return true;
@@ -3487,6 +3492,8 @@ Script.prototype.isPushOnly = function isPushOnly() {
     }
     if (op > opcodes.OP_16)
       return false;
+    if (op >= opcodes.OP_PUSHDATA1 && op <= opcodes.OP_PUSHDATA4)
+      return false;
   }
   return true;
 };
@@ -3509,6 +3516,9 @@ Script.prototype.getSigops = function getSigops(accurate) {
     if (Script.isPush(op))
       continue;
 
+    if (op >= opcodes.OP_PUSHDATA1 && op <= opcodes.OP_PUSHDATA4)
+      return 0;
+
     if (constants.opcodesByVal[op] == null)
       return 0;
 
@@ -4075,6 +4085,19 @@ Script.fromRaw = function fromRaw(data, enc) {
  * @returns {Array} Script code.
  */
 
+Script.isPushOp = function isPushOp(op) {
+  if (Buffer.isBuffer(op)) {
+    if (!Script.checkPush(op))
+      return false;
+    return true;
+  }
+  if (op > opcodes.OP_16)
+    return false;
+  if (op >= opcodes.OP_PUSHDATA1 && op <= opcodes.OP_PUSHDATA4)
+    return false;
+  return true;
+};
+
 Script.decode = function decode(buf) {
   var code = [];
   var off = 0;
@@ -4130,6 +4153,99 @@ Script.decode = function decode(buf) {
   return code;
 };
 
+Script.decode = function decode(buf) {
+  var code = [];
+  var p = new BufferReader(buf, true);
+  var off = 0;
+  var op, size;
+
+  assert(Buffer.isBuffer(buf));
+
+  while (p.left()) {
+    op = p.readU8();
+    if (op >= 0x01 && op <= 0x4b) {
+      data = p.readBytes(Math.min(p.left(), op));
+      utils.hidden(data, 'pushdata', {
+        opcode: null,
+        size: op
+      });
+      code.push(data);
+    } else if (op === opcodes.OP_PUSHDATA1) {
+      if (p.left() < 1) {
+        code.push(op);
+        while (p.left())
+          code.push(p.readU8());
+        continue;
+      }
+      size = p.readU8();
+      if (p.left() < size) {
+        code.push(op);
+        code.push(size);
+        while (p.left())
+          code.push(p.readU8());
+        continue;
+      }
+      data = p.readBytes(Math.min(p.left(), size));
+      utils.hidden(data, 'pushdata', {
+        opcode: op,
+        size: size
+      });
+      code.push(data);
+    } else if (op === opcodes.OP_PUSHDATA2) {
+      if (p.left() < 2) {
+        code.push(op);
+        while (p.left())
+          code.push(p.readU8());
+        continue;
+      }
+      size = p.readU16();
+      if (p.left() < size) {
+        code.push(op);
+        code.push(size & 0xff);
+        code.push((size >>> 8) & 0xff);
+        while (p.left())
+          code.push(p.readU8());
+        continue;
+      }
+      data = p.readBytes(Math.min(p.left(), size));
+      utils.hidden(data, 'pushdata', {
+        opcode: op,
+        size: size
+      });
+      code.push(data);
+    } else if (op === opcodes.OP_PUSHDATA4) {
+      if (p.left() < 4) {
+        code.push(op);
+        while (p.left())
+          code.push(p.readU8());
+        continue;
+      }
+      size = p.readU32();
+      if (p.left() < size) {
+        code.push(op);
+        code.push(size & 0xff);
+        code.push((size >>> 8) & 0xff);
+        code.push((size >>> 16) & 0xff);
+        code.push((size >>> 24) & 0xff);
+        while (p.left())
+          code.push(p.readU8());
+        continue;
+      }
+      data = p.readBytes(Math.min(p.left(), size));
+      utils.hidden(data, 'pushdata', {
+        opcode: op,
+        size: size
+      });
+      code.push(data);
+    } else {
+      code.push(op);
+    }
+  }
+
+  return code;
+};
+
+
 /**
  * Encode and serialize script code. This will _not_
  * include the varint size at the start. This will