Make a few tweaks to the changes in merge cc83ea8

- Not necessarily wrong, just not how I want it.
- Fixes a build error in LoanBroker_test
- In CreateOffer, fixes a logic error where _no_ offers will work if
  PermissionedDex amendment is enabled, and FlowCross is not

src/libxrpl/protocol/STTx.cpp

@@ -495,6 +495,8 @@ multiSignHelper(
         auto const accountID = signer.getAccountID(sfAccount);
 
         // The account owner may not usually multisign for themselves.
+        // If they can, txnAccountID will be unseated, which is not equal to any
+        // value.
         if (txnAccountID == accountID)
             return Unexpected("Invalid multisigner.");
 
@@ -556,7 +558,7 @@ STTx::checkBatchMultiSign(
         batchSigner,
         std::nullopt,
         fullyCanonical,
-        [&dataStart](AccountID const& accountID) mutable -> Serializer {
+        [&dataStart](AccountID const& accountID) -> Serializer {
             Serializer s = dataStart;
             finishMultiSigningData(accountID, s);
             return s;
@@ -588,7 +590,7 @@ STTx::checkMultiSign(
         sigObject,
         txnAccountID,
         fullyCanonical,
-        [&dataStart](AccountID const& accountID) mutable -> Serializer {
+        [&dataStart](AccountID const& accountID) -> Serializer {
             Serializer s = dataStart;
             finishMultiSigningData(accountID, s);
             return s;
@@ -620,11 +622,12 @@ STTx::getBatchTransactionIDs() const
     XRPL_ASSERT(
         getFieldArray(sfRawTransactions).size() != 0,
         "STTx::getBatchTransactionIDs : empty raw transactions");
-    if (batch_txn_ids_.size() != 0)
-        return batch_txn_ids_;
-
-    for (STObject const& rb : getFieldArray(sfRawTransactions))
-        batch_txn_ids_.push_back(rb.getHash(HashPrefix::transactionID));
+    // Don't early return so that the size check is always done.
+    if (batch_txn_ids_.size() == 0)
+    {
+        for (STObject const& rb : getFieldArray(sfRawTransactions))
+            batch_txn_ids_.push_back(rb.getHash(HashPrefix::transactionID));
+    }
 
     XRPL_ASSERT(
         batch_txn_ids_.size() == getFieldArray(sfRawTransactions).size(),

src/test/app/LoanBroker_test.cpp

@@ -197,6 +197,8 @@ class LoanBroker_test : public beast::unit_test::suite
 
             auto verifyCoverAmount =
                 [&env, &vault, &broker, &pseudoAccount, this](auto n) {
+                    using namespace jtx;
+
                     auto const amount = vault.asset(n);
                     BEAST_EXPECT(
                         broker->at(sfCoverAvailable) == amount.number());

src/test/jtx/TestHelpers.h

@@ -615,7 +615,7 @@ create(
 
 }  // namespace check
 
-static constexpr FeeLevel64 baseFeeLevel{256};
+static constexpr FeeLevel64 baseFeeLevel{TxQ::baseLevel};
 static constexpr FeeLevel64 minEscalationFeeLevel = baseFeeLevel * 500;
 
 template <class Suite>

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

@@ -48,12 +48,9 @@ CreateOffer::isEnabled(PreflightContext const& ctx)
 {
     // Permissioned offers should use the PE (which must be enabled by
     // featureFlowCross amendment)
-    if (ctx.rules.enabled(featurePermissionedDEX) &&
-        !ctx.rules.enabled(featureFlowCross))
-        return false;
-
     return (!ctx.tx.isFieldPresent(sfDomainID)) ||
-        ctx.rules.enabled(featurePermissionedDEX);
+        (ctx.rules.enabled(featurePermissionedDEX) &&
+         ctx.rules.enabled(featureFlowCross));
 }
 
 std::uint32_t