From 440e7e3ebc571adf02016c2b860607ff23f905a5 Mon Sep 17 00:00:00 2001
From: Gregory Tsipenyuk <gtsipenyuk@ripple.com>
Date: Mon, 8 Jun 2026 18:44:24 -0400
Subject: [PATCH] Address reviewer's feedback.

---
 src/libxrpl/protocol/STIssue.cpp   | 12 +++++++-----
 src/test/protocol/STIssue_test.cpp | 25 +++++++++----------------
 2 files changed, 16 insertions(+), 21 deletions(-)

diff --git a/src/libxrpl/protocol/STIssue.cpp b/src/libxrpl/protocol/STIssue.cpp
index bbf32f442b..4d80f2df3b 100644
--- a/src/libxrpl/protocol/STIssue.cpp
+++ b/src/libxrpl/protocol/STIssue.cpp
@@ -47,8 +47,9 @@ STIssue::STIssue(SerialIter& sit, SField const& name) : STBase{name}
         {
             MPTID mptID;
             std::uint32_t sequence = sit.get32();
-            // Preserve the existing LE memcpy result on every host endian.
-            // Wire 04 03 02 01 becomes MPTID bytes 01 02 03 04 on both.
+            // MPTID stores the sequence in canonical big-endian bytes. STIssue
+            // ledger bytes are the legacy LE-host encoding, so convert the
+            // native get32() value to LE bytes before copying into the MPTID.
             sequence = boost::endian::native_to_little(sequence);
             static_assert(MPTID::size() == sizeof(sequence) + sizeof(currencyOrAccount));
             memcpy(mptID.data(), &sequence, sizeof(sequence));
@@ -105,9 +106,10 @@ STIssue::add(Serializer& s) const
             s.addBitString(noAccount());
             std::uint32_t sequence = 0;
             memcpy(&sequence, issue.getMptID().data(), sizeof(sequence));
-            // Preserve the existing LE ledger bytes on every host endian.
-            // MPTID bytes 01 02 03 04 become wire bytes 04 03 02 01 on both.
-            sequence = boost::endian::native_to_little(sequence);
+            // The MPTID bytes are canonical big-endian. Interpret those bytes
+            // as the legacy LE-host value so add32() writes the preserved
+            // STIssue wire bytes on every host endian.
+            sequence = boost::endian::little_to_native(sequence);
             s.add32(sequence);
         });
 }
diff --git a/src/test/protocol/STIssue_test.cpp b/src/test/protocol/STIssue_test.cpp
index 9856035cbb..24edb9ceea 100644
--- a/src/test/protocol/STIssue_test.cpp
+++ b/src/test/protocol/STIssue_test.cpp
@@ -14,6 +14,7 @@
 #include <xrpl/protocol/Serializer.h>
 #include <xrpl/protocol/UintTypes.h>
 
+#include <array>
 #include <cstdint>
 
 namespace xrpl::test {
@@ -149,23 +150,13 @@ public:
         using namespace jtx;
         Account const alice{"alice"};
 
-        struct Vector
-        {
-            std::uint32_t sequence;
-            std::uint32_t legacySequence;
-        };
-
         // 0x01020304 pins canonical MPTID bytes 01 02 03 04 and
         // preserved STIssue wire bytes 04 03 02 01 on BE and LE.
-        Vector const vectors[] = {
-            {.sequence = 0x00000001, .legacySequence = 0x01000000},
-            {.sequence = 0x01020304, .legacySequence = 0x04030201},
-            {.sequence = 0xa1b2c3d4, .legacySequence = 0xd4c3b2a1},
-        };
+        std::array<std::uint32_t, 3> const vectors = {0x00000001, 0x01020304, 0xa1b2c3d4};
 
-        for (auto const& vector : vectors)
+        for (auto const vector : vectors)
         {
-            MPTID const mptID = makeMptID(vector.sequence, alice);
+            MPTID const mptID = makeMptID(vector, alice);
             MPTIssue const issue{mptID};
             STIssue const stIssue(sfAsset, Asset{issue});
 
@@ -177,9 +168,11 @@ public:
             expected.addBitString(alice.id());
             expected.addBitString(noAccount());
             {
-                std::array<unsigned char, 4> bytes;
-                auto const seq = boost::endian::native_to_little(vector.sequence);
-                memcpy(bytes.data(), &seq, 4);
+                std::array<unsigned char, 4> const bytes{
+                    static_cast<unsigned char>(vector),
+                    static_cast<unsigned char>(vector >> 8),
+                    static_cast<unsigned char>(vector >> 16),
+                    static_cast<unsigned char>(vector >> 24)};
                 expected.addRaw(bytes.data(), bytes.size());
             }