WIP

include/xrpl/protocol/LedgerFormats.h

@@ -187,6 +187,7 @@ enum LedgerSpecificFlags {
     lsfMPTCanTrade = 0x00000010,
     lsfMPTCanTransfer = 0x00000020,
     lsfMPTCanClawback = 0x00000040,
+    lsfMPTMutableMeta = 0x00000080,
 
     // ltMPTOKEN
     lsfMPTAuthorized = 0x00000002,

include/xrpl/protocol/TxFlags.h

@@ -148,8 +148,9 @@ constexpr std::uint32_t const tfMPTCanEscrow               = lsfMPTCanEscrow;
 constexpr std::uint32_t const tfMPTCanTrade                = lsfMPTCanTrade;
 constexpr std::uint32_t const tfMPTCanTransfer             = lsfMPTCanTransfer;
 constexpr std::uint32_t const tfMPTCanClawback             = lsfMPTCanClawback;
+constexpr std::uint32_t const tfMPTMutableMeta             = lsfMPTMutableMeta;
 constexpr std::uint32_t const tfMPTokenIssuanceCreateMask  =
-  ~(tfUniversal | tfMPTCanLock | tfMPTRequireAuth | tfMPTCanEscrow | tfMPTCanTrade | tfMPTCanTransfer | tfMPTCanClawback);
+  ~(tfUniversal | tfMPTCanLock | tfMPTRequireAuth | tfMPTCanEscrow | tfMPTCanTrade | tfMPTCanTransfer | tfMPTCanClawback | tfMPTMutableMeta);
 
 // MPTokenAuthorize flags:
 constexpr std::uint32_t const tfMPTUnauthorize             = 0x00000001;

include/xrpl/protocol/detail/features.macro

@@ -35,6 +35,7 @@
 // If you add an amendment here, then do not forget to increment `numFeatures`
 // in include/xrpl/protocol/Feature.h.
 
+XRPL_FEATURE(MPTMutableMeta,             Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (AMMClawbackRounding,        Supported::no,  VoteBehavior::DefaultNo)
 XRPL_FEATURE(TokenEscrow,                Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (EnforceNFTokenTrustlineV2,  Supported::yes, VoteBehavior::DefaultNo)

include/xrpl/protocol/detail/transactions.macro

@@ -420,6 +420,7 @@ TRANSACTION(ttMPTOKEN_ISSUANCE_DESTROY, 55, MPTokenIssuanceDestroy, Delegation::
 TRANSACTION(ttMPTOKEN_ISSUANCE_SET, 56, MPTokenIssuanceSet, Delegation::delegatable, ({
     {sfMPTokenIssuanceID, soeREQUIRED},
     {sfHolder, soeOPTIONAL},
+    {sfMPTokenMetadata, soeOPTIONAL},
 }))
 
 /** This transaction type authorizes a MPToken instance */

src/test/app/MPToken_test.cpp

@@ -22,6 +22,7 @@
 #include <test/jtx/xchain_bridge.h>
 
 #include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/TxFlags.h>
 #include <xrpl/protocol/jss.h>
 
 namespace ripple {
@@ -86,6 +87,14 @@ class MPToken_test : public beast::unit_test::suite
                  .metadata = "",
                  .err = temMALFORMED});
 
+            // oversized metadata returns error
+            mptAlice.create(
+                {.maxAmt = 100,
+                 .assetScale = 0,
+                 .transferFee = 0,
+                 .metadata = std::string(2050, 'B'),
+                 .err = temMALFORMED});
+
             // MaximumAmout of 0 returns error
             mptAlice.create(
                 {.maxAmt = 0,
@@ -108,6 +117,29 @@ class MPToken_test : public beast::unit_test::suite
                  .metadata = "test",
                  .err = temMALFORMED});
         }
+
+        // test preflight tfMPTMutableMeta when feature is disabled
+        {
+            Env env{*this, features - featureMPTMutableMeta};
+            MPTTester mptAlice(env, alice);
+
+            mptAlice.create(
+                {.maxAmt = 100,
+                 .assetScale = 0,
+                 .transferFee = 0,
+                 .flags = tfMPTMutableMeta,
+                 .err = temDISABLED}
+            );
+
+                        mptAlice.create(
+                {.maxAmt = 100,
+                 .assetScale = 0,
+                 .transferFee = 0,
+                 .metadata = "abc",
+                 .flags = tfMPTMutableMeta,
+                 .err = temDISABLED}
+            );
+        }
     }
 
     void
@@ -512,6 +544,14 @@ class MPToken_test : public beast::unit_test::suite
                  .holder = alice,
                  .flags = tfMPTLock,
                  .err = temMALFORMED});
+
+            // Oversized metadata
+            mptAlice.set(
+                {.account = alice,
+                 .holder = alice,
+                 .metadata = std::string(2050, 'B'),
+                 .flags = tfMPTLock,
+                 .err = temMALFORMED});
         }
 
         // Validate fields in MPTokenIssuanceSet (preclaim)

src/test/jtx/impl/mpt.cpp

@@ -19,6 +19,7 @@
 
 #include <test/jtx.h>
 
+#include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/jss.h>
 
 namespace ripple {
@@ -231,6 +232,8 @@ MPTTester::set(MPTSet const& arg)
             Throw<std::runtime_error>("MPT has not been created");
         jv[sfMPTokenIssuanceID] = to_string(*id_);
     }
+    if (arg.metadata)
+        jv[sfMPTokenMetadata] = strHex(*arg.metadata);
     if (arg.holder)
         jv[sfHolder] = arg.holder->human();
     if (arg.delegate)

src/test/jtx/mpt.h

@@ -135,6 +135,7 @@ struct MPTSet
     std::optional<Account> account = std::nullopt;
     std::optional<Account> holder = std::nullopt;
     std::optional<MPTID> id = std::nullopt;
+    std::optional<std::string> metadata = std::nullopt;
     std::optional<std::uint32_t> ownerCount = std::nullopt;
     std::optional<std::uint32_t> holderCount = std::nullopt;
     std::optional<std::uint32_t> flags = std::nullopt;

src/xrpld/app/tx/detail/MPTokenIssuanceCreate.cpp

@@ -30,6 +30,8 @@ MPTokenIssuanceCreate::preflight(PreflightContext const& ctx)
 {
     if (!ctx.rules.enabled(featureMPTokensV1))
         return temDISABLED;
+    if (ctx.tx.isFlag(tfMPTMutableMeta) && !ctx.rules.enabled(featureMPTMutableMeta))
+        return temDISABLED;
 
     if (auto const ret = preflight1(ctx); !isTesSuccess(ret))
         return ret;

src/xrpld/app/tx/detail/MPTokenIssuanceSet.cpp

@@ -21,6 +21,9 @@
 #include <xrpld/app/tx/detail/MPTokenIssuanceSet.h>
 
 #include <xrpl/protocol/Feature.h>
+#include <xrpl/protocol/LedgerFormats.h>
+#include <xrpl/protocol/SField.h>
+#include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/TxFlags.h>
 
 namespace ripple {
@@ -30,6 +33,8 @@ MPTokenIssuanceSet::preflight(PreflightContext const& ctx)
 {
     if (!ctx.rules.enabled(featureMPTokensV1))
         return temDISABLED;
+    if (ctx.tx.isFieldPresent(sfMPTokenMetadata) && !ctx.rules.enabled(featureMPTMutableMeta))
+        return temDISABLED;
 
     if (auto const ret = preflight1(ctx); !isTesSuccess(ret))
         return ret;
@@ -43,6 +48,13 @@ MPTokenIssuanceSet::preflight(PreflightContext const& ctx)
     else if ((txFlags & tfMPTLock) && (txFlags & tfMPTUnlock))
         return temINVALID_FLAG;
 
+    if (auto const metadata = ctx.tx[~sfMPTokenMetadata])
+    {
+        // Note: metadata->length() == 0 is valid here, will erase metatdata
+        if (metadata->length() > maxMPTokenMetadataLength)
+            return temMALFORMED;
+    }
+
     auto const accountID = ctx.tx[sfAccount];
     auto const holderID = ctx.tx[~sfHolder];
     if (holderID && accountID == holderID)
@@ -97,6 +109,11 @@ MPTokenIssuanceSet::preclaim(PreclaimContext const& ctx)
     if (!sleMptIssuance)
         return tecOBJECT_NOT_FOUND;
 
+    if (ctx.tx.isFieldPresent(sfMPTokenMetadata)  && !sleMptIssuance->isFlag(lsfMPTMutableMeta))
+        return tecNO_PERMISSION;
+
+    // TODO check below is invalid if we are trying to update metadata
+
     // if the mpt has disabled locking
     if (!((*sleMptIssuance)[sfFlags] & lsfMPTCanLock))
         return tecNO_PERMISSION;