Add AMMClawback Transaction (XLS-0073d)

include/xrpl/protocol/Feature.h

@@ -80,7 +80,7 @@ namespace detail {
 // Feature.cpp. Because it's only used to reserve storage, and determine how
 // large to make the FeatureBitset, it MAY be larger. It MUST NOT be less than
 // the actual number of amendments. A LogicError on startup will verify this.
-static constexpr std::size_t numFeatures = 80;
+static constexpr std::size_t numFeatures = 81;
 
 /** Amendments that this server supports and the default voting behavior.
    Whether they are enabled depends on the Rules defined in the validated

include/xrpl/protocol/TxFlags.h

@@ -207,6 +207,10 @@ constexpr std::uint32_t tfDepositSubTx =
 constexpr std::uint32_t tfWithdrawMask = ~(tfUniversal | tfWithdrawSubTx);
 constexpr std::uint32_t tfDepositMask = ~(tfUniversal | tfDepositSubTx);
 
+// AMMClawback flags:
+constexpr std::uint32_t tfClawTwoAssets                = 0x00000001;
+constexpr std::uint32_t tfAMMClawbackMask = ~(tfUniversal | tfClawTwoAssets);
+
 // BridgeModify flags:
 constexpr std::uint32_t tfClearAccountCreateAmount     = 0x00010000;
 constexpr std::uint32_t tfBridgeModifyMask = ~(tfUniversal | tfClearAccountCreateAmount);

include/xrpl/protocol/detail/features.macro

@@ -95,6 +95,7 @@ XRPL_FIX    (1513,                       Supported::yes, VoteBehavior::DefaultYe
 XRPL_FEATURE(FlowCross,                  Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(Flow,                       Supported::yes, VoteBehavior::DefaultYes)
 XRPL_FEATURE(OwnerPaysFee,               Supported::no,  VoteBehavior::DefaultNo)
+XRPL_FEATURE(AMMClawback,                Supported::yes,  VoteBehavior::DefaultYes)
 
 // The following amendments are obsolete, but must remain supported
 // because they could potentially get enabled.

include/xrpl/protocol/detail/transactions.macro

@@ -227,6 +227,14 @@ TRANSACTION(ttCLAWBACK, 30, Clawback, ({
     {sfHolder, soeOPTIONAL},
 }))
 
+/** This transaction claws back tokens from an AMM pool. */
+TRANSACTION(ttAMM_CLAWBACK, 31, AMMClawback, ({
+    {sfHolder, soeREQUIRED},
+    {sfAsset, soeREQUIRED},
+    {sfAsset2, soeREQUIRED},
+    {sfAmount, soeOPTIONAL},
+}))
+
 /** This transaction type creates an AMM instance */
 TRANSACTION(ttAMM_CREATE, 35, AMMCreate, ({
     {sfAmount, soeREQUIRED},

include/xrpl/protocol/jss.h

@@ -73,6 +73,7 @@ JSS(Escrow);               // ledger type.
 JSS(Fee);                  // in/out: TransactionSign; field.
 JSS(FeeSettings);          // ledger type.
 JSS(Flags);                // in/out: TransactionSign; field.
+JSS(Holder);               // field.
 JSS(Invalid);              //
 JSS(LastLedgerSequence);   // in: TransactionSign; field
 JSS(LastUpdateTime);       // field.

src/libxrpl/protocol/TER.cpp

@@ -160,7 +160,7 @@ transResults()
 
         MAKE_ERROR(temMALFORMED,                 "Malformed transaction."),
         MAKE_ERROR(temBAD_AMM_TOKENS,            "Malformed: Invalid LPTokens."),
-        MAKE_ERROR(temBAD_AMOUNT,                "Can only send positive amounts."),
+        MAKE_ERROR(temBAD_AMOUNT,                "Malformed: Bad amount."),
         MAKE_ERROR(temBAD_CURRENCY,              "Malformed: Bad currency."),
         MAKE_ERROR(temBAD_EXPIRATION,            "Malformed: Bad expiration."),
         MAKE_ERROR(temBAD_FEE,                   "Invalid fee, negative or not XRP."),