[BUG] Undo previous commit making append_byte_array too loose.

This commit introduces an alternative way of setting the canonical signature
flag, without compromising the strictness of append_byte_array input
sanitizing.

src/js/ripple/serializedtypes.js

@@ -120,8 +120,6 @@ SerializedType.prototype.parse_varint = function (so) {
  * The result is appended to the serialized object ('so').
  */
 function append_byte_array(so, val, bytes) {
-  val = val >>> 0;
-
   if (!isNumber(val)) {
     throw new Error('Value is not a number');
   }

src/js/ripple/transaction.js

@@ -62,9 +62,7 @@ function Transaction(remote) {
   this.remote = remote;
 
   // Transaction data
-  this.tx_json = {
-    Flags: Transaction.defaultFlags
-  };
+  this.tx_json = { Flags: 0 };
 
   this._secret = void(0);
   this._build_path = false;
@@ -75,11 +73,13 @@ function Transaction(remote) {
   // Index at which transaction was submitted
   this.submitIndex = void(0);
 
+  this.canonical = true;
+
   // We aren't clever enough to eschew preventative measures so we keep an array
   // of all submitted transactionIDs (which can change due to load_factor
   // effecting the Fee amount). This should be populated with a transactionID
   // any time it goes on the network
-  this.submittedIDs = [ ]
+  this.submittedIDs = [ ];
 
   function finalize(message) {
     if (!self.finalized) {
@@ -151,8 +151,6 @@ Transaction.flags = {
   }
 };
 
-Transaction.defaultFlags = 0 | Transaction.flags.Universal.FullyCanonicalSig;
-
 Transaction.formats = require('./binformat').tx;
 
 Transaction.prototype.consts = {
@@ -282,6 +280,15 @@ Transaction.prototype.complete = function() {
     this.tx_json.SigningPubKey = key.to_hex_pub();
   }
 
+  // Set canonical flag - this enables canonicalized signature checking
+  if (this.canonical) {
+    this.tx_json.Flags |= Transaction.flags.Universal.FullyCanonicalSig;
+
+    // JavaScript converts operands to 32-bit signed ints before doing bitwise
+    // operations. We need to convert it back to an unsigned int.
+    this.tx_json.Flags = this.tx_json.Flags >>> 0;
+  }
+
   return this.tx_json;
 };