diff --git a/package.json b/package.json
index 18b461f0e..2d22eb117 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ripple-lib",
-  "version": "0.7.8",
+  "version": "0.7.9",
   "description": "Ripple JavaScript client library",
 
   "files": [
diff --git a/src/cpp/ripple/AccountSetTransactor.cpp b/src/cpp/ripple/AccountSetTransactor.cpp
index 9ffa635e5..4e8c13834 100644
--- a/src/cpp/ripple/AccountSetTransactor.cpp
+++ b/src/cpp/ripple/AccountSetTransactor.cpp
@@ -44,7 +44,7 @@ TER AccountSetTransactor::doApply()
 		uFlagsOut	|= lsfRequireAuth;
 	}
 
-	if (uTxFlags & tfOptionalAuth)
+	if ((uTxFlags & tfOptionalAuth) && isSetBit(uFlagsIn, lsfRequireAuth))
 	{
 		cLog(lsINFO) << "AccountSet: Clear RequireAuth.";
 
@@ -62,16 +62,16 @@ TER AccountSetTransactor::doApply()
 		return temINVALID_FLAG;
 	}
 
-	if (uTxFlags & tfRequireDestTag)
+	if ((uTxFlags & tfOptionalDestTag) && !isSetBit(uFlagsIn, lsfRequireDestTag))
 	{
-		cLog(lsINFO) << "AccountSet: Set RequireDestTag.";
+		cLog(lsINFO) << "AccountSet: Set lsfRequireDestTag.";
 
 		uFlagsOut	|= lsfRequireDestTag;
 	}
 
-	if (uTxFlags & tfOptionalDestTag)
+	if ((uTxFlags & tfOptionalDestTag) && isSetBit(uFlagsIn, lsfRequireDestTag))
 	{
-		cLog(lsINFO) << "AccountSet: Clear RequireDestTag.";
+		cLog(lsINFO) << "AccountSet: Clear lsfRequireDestTag.";
 
 		uFlagsOut	&= ~lsfRequireDestTag;
 	}
@@ -79,6 +79,31 @@ TER AccountSetTransactor::doApply()
 	if (uFlagsIn != uFlagsOut)
 		mTxnAccount->setFieldU32(sfFlags, uFlagsOut);
 
+	//
+	// DisallowXRP
+	//
+
+	if ((tfDisallowXRP|tfAllowXRP) == (uTxFlags & (tfDisallowXRP|tfAllowXRP)))
+	{
+		cLog(lsINFO) << "AccountSet: Malformed transaction: Contradictory flags set.";
+
+		return temINVALID_FLAG;
+	}
+
+	if ((uTxFlags & tfDisallowXRP) && !isSetBit(uFlagsIn, lsfDisallowXRP))
+	{
+		cLog(lsINFO) << "AccountSet: Set lsfDisallowXRP.";
+
+		uFlagsOut	|= lsfDisallowXRP;
+	}
+
+	if ((uTxFlags & tfAllowXRP) && isSetBit(uFlagsIn, lsfDisallowXRP))
+	{
+		cLog(lsINFO) << "AccountSet: Clear lsfDisallowXRP.";
+
+		uFlagsOut	&= ~lsfDisallowXRP;
+	}
+
 	//
 	// EmailHash
 	//
diff --git a/src/cpp/ripple/LedgerFormats.h b/src/cpp/ripple/LedgerFormats.h
index 537f3f193..f9f0a737b 100644
--- a/src/cpp/ripple/LedgerFormats.h
+++ b/src/cpp/ripple/LedgerFormats.h
@@ -42,6 +42,7 @@ enum LedgerSpecificFlags
 	lsfPasswordSpent	= 0x00010000,	// True, if password set fee is spent.
 	lsfRequireDestTag	= 0x00020000,	// True, to require a DestinationTag for payments.
 	lsfRequireAuth		= 0x00040000,	// True, to require a authorization to hold IOUs.
+	lsfDisallowXRP		= 0x00080000,	// True, to disallow sending XRP.
 
 	// ltOFFER
 	lsfPassive			= 0x00010000,
diff --git a/src/cpp/ripple/PaymentTransactor.cpp b/src/cpp/ripple/PaymentTransactor.cpp
index 65c4aedf3..f81832db9 100644
--- a/src/cpp/ripple/PaymentTransactor.cpp
+++ b/src/cpp/ripple/PaymentTransactor.cpp
@@ -146,7 +146,7 @@ TER PaymentTransactor::doApply()
 	{
 		cLog(lsINFO) << "Payment: Malformed transaction: DestinationTag required.";
 
-		return temDST_TAG_NEEDED;
+		return tefDST_TAG_NEEDED;
 	}
 	else
 	{
diff --git a/src/cpp/ripple/TransactionErr.cpp b/src/cpp/ripple/TransactionErr.cpp
index 7df6880d4..bdd1dcee2 100644
--- a/src/cpp/ripple/TransactionErr.cpp
+++ b/src/cpp/ripple/TransactionErr.cpp
@@ -34,6 +34,7 @@ bool transResultInfo(TER terCode, std::string& strToken, std::string& strHuman)
 		{	tefBAD_LEDGER,			"tefBAD_LEDGER",			"Ledger in unexpected state."							},
 		{	tefCLAIMED,				"tefCLAIMED",				"Can not claim a previously claimed account."			},
 		{	tefCREATED,				"tefCREATED",				"Can't add an already created account."					},
+		{	tefDST_TAG_NEEDED,		"tefDST_TAG_NEEDED",		"Destination tag required."								},
 		{	tefEXCEPTION,			"tefEXCEPTION",				"Unexpected program state."								},
 		{	tefGEN_IN_USE,			"tefGEN_IN_USE",			"Generator already in use."								},
 		{	tefINTERNAL,			"tefINTERNAL",				"Internal error."										},
@@ -71,7 +72,6 @@ bool transResultInfo(TER terCode, std::string& strToken, std::string& strHuman)
 		{	temBAD_SEND_XRP_PATHS,		"temBAD_SEND_XRP_PATHS",		"Malformed: Paths are not allowed for XRP to XRP."				},
 		{	temDST_IS_SRC,			"temDST_IS_SRC",			"Destination may not be source."						},
 		{	temDST_NEEDED,			"temDST_NEEDED",			"Destination not specified."							},
-		{	temDST_TAG_NEEDED,		"temDST_TAG_NEEDED",		"Destination tag required."								},
 		{	temINVALID,				"temINVALID",				"The transaction is ill-formed."						},
 		{	temINVALID_FLAG,		"temINVALID_FLAG",			"The transaction has an invalid flag."					},
 		{	temREDUNDANT,			"temREDUNDANT",				"Sends same currency to self."							},
diff --git a/src/cpp/ripple/TransactionErr.h b/src/cpp/ripple/TransactionErr.h
index 2d00c2f6a..2e18d5f16 100644
--- a/src/cpp/ripple/TransactionErr.h
+++ b/src/cpp/ripple/TransactionErr.h
@@ -51,7 +51,6 @@ enum TER	// aka TransactionEngineResult
 	temBAD_SEQUENCE,
 	temDST_IS_SRC,
 	temDST_NEEDED,
-	temDST_TAG_NEEDED,
 	temINVALID,
 	temINVALID_FLAG,
 	temREDUNDANT,
@@ -78,6 +77,7 @@ enum TER	// aka TransactionEngineResult
 	tefBAD_LEDGER,
 	tefCLAIMED,
 	tefCREATED,
+	tefDST_TAG_NEEDED,
 	tefEXCEPTION,
 	tefGEN_IN_USE,
 	tefINTERNAL,
diff --git a/src/cpp/ripple/TransactionFormats.h b/src/cpp/ripple/TransactionFormats.h
index 7b285c73d..b7a5d079b 100644
--- a/src/cpp/ripple/TransactionFormats.h
+++ b/src/cpp/ripple/TransactionFormats.h
@@ -64,7 +64,11 @@ const uint32 tfRequireDestTag		= 0x00010000;
 const uint32 tfOptionalDestTag		= 0x00020000;
 const uint32 tfRequireAuth			= 0x00040000;
 const uint32 tfOptionalAuth			= 0x00080000;
-const uint32 tfAccountSetMask		= ~(tfRequireDestTag|tfOptionalDestTag|tfRequireAuth|tfOptionalAuth);
+const uint32 tfDisallowXRP			= 0x00100000;
+const uint32 tfAllowXRP				= 0x00200000;
+const uint32 tfAccountSetMask		= ~(tfRequireDestTag|tfOptionalDestTag
+										|tfRequireAuth|tfOptionalAuth
+										|tfDisallowXRP|tfAllowXRP);
 
 // OfferCreate flags:
 const uint32 tfPassive				= 0x00010000;
diff --git a/src/cpp/ripple/TrustSetTransactor.cpp b/src/cpp/ripple/TrustSetTransactor.cpp
index 8365fc1a6..55133bc11 100644
--- a/src/cpp/ripple/TrustSetTransactor.cpp
+++ b/src/cpp/ripple/TrustSetTransactor.cpp
@@ -17,7 +17,7 @@ TER TrustSetTransactor::doApply()
 	const bool			bHigh			= mTxnAccountID > uDstAccountID;		// true, iff current is high account.
 
 	uint32				uQualityIn		= bQualityIn ? mTxn.getFieldU32(sfQualityIn) : 0;
-	uint32				uQualityOut		= bQualityIn ? mTxn.getFieldU32(sfQualityOut) : 0;
+	uint32				uQualityOut		= bQualityOut ? mTxn.getFieldU32(sfQualityOut) : 0;
 
 	if (bQualityIn && QUALITY_ONE == uQualityIn)
 		uQualityIn	= 0;
diff --git a/src/js/amount.js b/src/js/amount.js
index 3a6b2797e..01a65d48a 100644
--- a/src/js/amount.js
+++ b/src/js/amount.js
@@ -46,7 +46,7 @@ var Amount = function () {
   //  integer : XRP
   //  { 'value' : ..., 'currency' : ..., 'issuer' : ...}
 
-  this._value	    = new BigInteger();	// NaN for bad value. Always positive for non-XRP.
+  this._value	    = new BigInteger();	// NaN for bad value. Always positive.
   this._offset	    = 0;	        // Always 0 for XRP.
   this._is_native   = true;		// Default to XRP. Only valid if value is not NaN.
   this._is_negative = false;
@@ -226,14 +226,6 @@ Amount.prototype.compareTo = function (v) {
   if (!this.is_comparable(v)) {
     result  = Amount.NaN();
   }
-  else if (this._is_native) {
-    result  = this._value.compareTo(v._value);
-
-    if (result > 1)
-      result  = 1;
-    else if (result < -1)
-      result  = -1;
-  }
   else if (this._is_negative !== v._is_negative) {
     result  = this._is_negative ? -1 : 1;
   }
@@ -242,15 +234,15 @@ Amount.prototype.compareTo = function (v) {
                 ? 1
                 : v._value.equals(BigInteger.ZERO)
                   ? 0
-                  : 1;
+                  : -1;
   }
   else if (v._value.equals(BigInteger.ZERO)) {
     result  = 1;
   }
-  else if (this._offset > v._offset) {
+  else if (!this._is_native && this._offset > v._offset) {
     result  = this._is_negative ? -1 : 1;
   }
-  else if (this._offset < v._offset) {
+  else if (!this._is_native && this._offset < v._offset) {
     result  = this._is_negative ? 1 : -1;
   }
   else {
diff --git a/src/js/transaction.js b/src/js/transaction.js
index 06189c6df..c83ad51da 100644
--- a/src/js/transaction.js
+++ b/src/js/transaction.js
@@ -116,6 +116,7 @@ Transaction.flags = {
     'Passive'                 : 0x00010000,
     'ImmediateOrCancel'       : 0x00020000,
     'FillOrKill'              : 0x00040000,
+    'Sell'                    : 0x00080000,
   },
 
   'Payment' : {
@@ -575,6 +576,8 @@ Transaction.prototype.offer_cancel = function (src, sequence) {
   return this;
 };
 
+// Options:
+//  .set_flags()
 // --> expiration : Date or Number
 Transaction.prototype.offer_create = function (src, taker_pays, taker_gets, expiration) {
   this._secret                  = this._account_secret(src);