Check AMM/OfferCreate for MPT amounts

* Add type restriction to StepImp and flow()
* Add temMPT_NOT_SUPPORTED_BY_TX

src/ripple/app/paths/impl/Steps.h

@@ -445,6 +445,8 @@ toStrands(
 
 /// @cond INTERNAL
 template <class TIn, class TOut, class TDerived>
+requires (!(std::is_same_v<TIn, STAmount> || std::is_same_v<TIn, MPTAmount> ||
+    std::is_same_v<TOut, STAmount> || std::is_same_v<TOut, MPTAmount>))
 struct StepImp : public Step
 {
     explicit StepImp() = default;

src/ripple/app/paths/impl/StrandFlow.h

@@ -551,6 +551,8 @@ class ActiveStrands
    sandbox
 */
 template <class TInAmt, class TOutAmt>
+requires (!(std::is_same_v<TInAmt, STAmount> || std::is_same_v<TInAmt, MPTAmount> ||
+    std::is_same_v<TOutAmt, STAmount> || std::is_same_v<TOutAmt, MPTAmount>))
 FlowResult<TInAmt, TOutAmt>
 flow(
     PaymentSandbox const& baseView,

src/ripple/app/tx/impl/AMMCreate.cpp

@@ -50,6 +50,12 @@ AMMCreate::preflight(PreflightContext const& ctx)
     auto const amount = ctx.tx[sfAmount];
     auto const amount2 = ctx.tx[sfAmount2];
 
+    if (amount.isMPT() || amount2.isIssue())
+    {
+        JLOG(ctx.j.debug()) << "AMM Instance: MPT is not supported.";
+        return temMPT_NOT_SUPPORTED_BY_TX;
+    }
+
     if (amount.issue() == amount2.issue())
     {
         JLOG(ctx.j.debug())

src/ripple/app/tx/impl/CreateOffer.cpp

@@ -83,6 +83,9 @@ CreateOffer::preflight(PreflightContext const& ctx)
     STAmount saTakerPays = tx[sfTakerPays];
     STAmount saTakerGets = tx[sfTakerGets];
 
+    if (saTakerPays.isMPT() || saTakerGets.isMPT())
+        return temMPT_NOT_SUPPORTED_BY_TX;
+
     if (!isLegalNet(saTakerPays) || !isLegalNet(saTakerGets))
         return temBAD_AMOUNT;
 

src/ripple/protocol/TER.h

@@ -136,6 +136,8 @@ enum TEMcodes : TERUnderlyingType {
     temXCHAIN_BRIDGE_BAD_REWARD_AMOUNT,
 
     temEMPTY_DID,
+
+    temMPT_NOT_SUPPORTED_BY_TX
 };
 
 //------------------------------------------------------------------------------

src/ripple/protocol/impl/TER.cpp

@@ -183,6 +183,7 @@ transResults()
         MAKE_ERROR(temEMPTY_DID,                 "Malformed: No DID data provided."),
         MAKE_ERROR(temINVALID,                   "The transaction is ill-formed."),
         MAKE_ERROR(temINVALID_FLAG,              "The transaction has an invalid flag."),
+        MAKE_ERROR(temMPT_NOT_SUPPORTED_BY_TX,   "MPT is not supported by the transaction."),
         MAKE_ERROR(temREDUNDANT,                 "The transaction is redundant."),
         MAKE_ERROR(temRIPPLE_EMPTY,              "PathSet with no paths."),
         MAKE_ERROR(temUNCERTAIN,                 "In process of determining result. Never returned."),