From 1b295c7c001d4148d9e62db3b96dd660f5a487ca Mon Sep 17 00:00:00 2001
From: Ed Hennis <ed@ripple.com>
Date: Wed, 10 Sep 2025 20:33:01 -0400
Subject: [PATCH] Use Permission to check if a Transactor is enabled

- Adds a Permission::getTxFeature lookup function to find the
  controlling amendment for a Transactor, if any.
- Returns temDISABLED from preflight if there is an amendment and it's
  not enabled.
- Still need to go through and remove all the now-redundant isEnabled
  functions.
---
 include/xrpl/protocol/Permissions.h  |  3 +++
 src/libxrpl/protocol/Permissions.cpp | 21 +++++++++++++++------
 src/xrpld/app/tx/detail/Transactor.h |  9 +++++++++
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/include/xrpl/protocol/Permissions.h b/include/xrpl/protocol/Permissions.h
index cf49ff7382..924a5af0da 100644
--- a/include/xrpl/protocol/Permissions.h
+++ b/include/xrpl/protocol/Permissions.h
@@ -83,6 +83,9 @@ public:
     std::optional<TxType>
     getGranularTxType(GranularPermissionType const& gpType) const;
 
+    std::optional<std::reference_wrapper<uint256 const>> const
+    getTxFeature(TxType txType) const;
+
     bool
     isDelegatable(std::uint32_t const& permissionValue, Rules const& rules)
         const;
diff --git a/src/libxrpl/protocol/Permissions.cpp b/src/libxrpl/protocol/Permissions.cpp
index 781799f128..af4b7e42c4 100644
--- a/src/libxrpl/protocol/Permissions.cpp
+++ b/src/libxrpl/protocol/Permissions.cpp
@@ -131,6 +131,19 @@ Permission::getGranularTxType(GranularPermissionType const& gpType) const
     return std::nullopt;
 }
 
+std::optional<std::reference_wrapper<uint256 const>> const
+Permission::getTxFeature(TxType txType) const
+{
+    auto const txFeaturesIt = txFeatureMap_.find(txType);
+    XRPL_ASSERT(
+        txFeaturesIt != txFeatureMap_.end(),
+        "ripple::Permissions::isDelegatable : tx exists in txFeatureMap_");
+
+    if (txFeaturesIt->second == uint256{})
+        return std::nullopt;
+    return txFeaturesIt->second;
+}
+
 bool
 Permission::isDelegatable(
     std::uint32_t const& permissionValue,
@@ -150,16 +163,12 @@ Permission::isDelegatable(
         if (it == delegatableTx_.end())
             return false;
 
-        auto const txFeaturesIt = txFeatureMap_.find(txType);
-        XRPL_ASSERT(
-            txFeaturesIt != txFeatureMap_.end(),
-            "ripple::Permissions::isDelegatable : tx exists in txFeatureMap_");
+        auto const feature = getTxFeature(txType);
 
         // fixDelegateV1_1: Delegation is only allowed if the required amendment
         // for the transaction is enabled. For transactions that do not require
         // an amendment, delegation is always allowed.
-        if (txFeaturesIt->second != uint256{} &&
-            !rules.enabled(txFeaturesIt->second))
+        if (feature && !rules.enabled(*feature))
             return false;
     }
 
diff --git a/src/xrpld/app/tx/detail/Transactor.h b/src/xrpld/app/tx/detail/Transactor.h
index 29a8df7574..9b5638d9e1 100644
--- a/src/xrpld/app/tx/detail/Transactor.h
+++ b/src/xrpld/app/tx/detail/Transactor.h
@@ -392,6 +392,15 @@ Transactor::invokePreflight(PreflightContext const& ctx)
     // TODO: If #5650 is merged, use its transaction -> amendment lookup here to
     // do a first-pass check. Rewrite or remove any `isEnabled` overloads that
     // check those default amendments.
+
+    // Using this lookup does NOT require checking the fixDelegateV1_1. The data
+    // exists regardless of whether it is enabled.
+    auto const feature =
+        Permission::getInstance().getTxFeature(ctx.tx.getTxnType());
+
+    if (feature && !ctx.rules.enabled(*feature))
+        return temDISABLED;
+
     if (!T::isEnabled(ctx))
         return temDISABLED;