From f15f790618d328abd207d55e6291229eb2a8643f Mon Sep 17 00:00:00 2001
From: Cory Fields <cory-nospam-@coryfields.com>
Date: Thu, 7 Sep 2023 15:20:24 +0000
Subject: [PATCH] Remove version/hashing options from
 CBlockLocator/CDiskBlockIndex

---
 src/chain.h            | 12 ++++++++++--
 src/primitives/block.h | 14 +++++++++++---
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/chain.h b/src/chain.h
index 2e1fb37bec0..7806720ce9e 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -388,6 +388,14 @@ const CBlockIndex* LastCommonAncestor(const CBlockIndex* pa, const CBlockIndex*
 /** Used to marshal pointers into hashes for db storage. */
 class CDiskBlockIndex : public CBlockIndex
 {
+    /** Historically CBlockLocator's version field has been written to disk
+     * streams as the client version, but the value has never been used.
+     *
+     * Hard-code to the highest client version ever written.
+     * SerParams can be used if the field requires any meaning in the future.
+     **/
+    static constexpr int DUMMY_VERSION = 259900;
+
 public:
     uint256 hashPrev;
 
@@ -404,8 +412,8 @@ public:
     SERIALIZE_METHODS(CDiskBlockIndex, obj)
     {
         LOCK(::cs_main);
-        int _nVersion = s.GetVersion();
-        if (!(s.GetType() & SER_GETHASH)) READWRITE(VARINT_MODE(_nVersion, VarIntMode::NONNEGATIVE_SIGNED));
+        int _nVersion = DUMMY_VERSION;
+        READWRITE(VARINT_MODE(_nVersion, VarIntMode::NONNEGATIVE_SIGNED));
 
         READWRITE(VARINT_MODE(obj.nHeight, VarIntMode::NONNEGATIVE_SIGNED));
         READWRITE(VARINT(obj.nStatus));
diff --git a/src/primitives/block.h b/src/primitives/block.h
index 861d362414b..99accfc7dd9 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -118,6 +118,15 @@ public:
  */
 struct CBlockLocator
 {
+    /** Historically CBlockLocator's version field has been written to network
+     * streams as the negotiated protocol version and to disk streams as the
+     * client version, but the value has never been used.
+     *
+     * Hard-code to the highest protocol version ever written to a network stream.
+     * SerParams can be used if the field requires any meaning in the future,
+     **/
+    static constexpr int DUMMY_VERSION = 70016;
+
     std::vector<uint256> vHave;
 
     CBlockLocator() {}
@@ -126,9 +135,8 @@ struct CBlockLocator
 
     SERIALIZE_METHODS(CBlockLocator, obj)
     {
-        int nVersion = s.GetVersion();
-        if (!(s.GetType() & SER_GETHASH))
-            READWRITE(nVersion);
+        int nVersion = DUMMY_VERSION;
+        READWRITE(nVersion);
         READWRITE(obj.vHave);
     }