From b6002b07a36f0d58dc6becd04bfcf78599056b7c Mon Sep 17 00:00:00 2001
From: glozow <gloriajzhao@gmail.com>
Date: Fri, 3 Dec 2021 18:00:00 +0000
Subject: [PATCH 1/2] MOVEONLY: update_lock_points to txmempool.h

---
 src/txmempool.cpp | 10 ----------
 src/txmempool.h   | 10 ++++++++++
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index fcfc27d38ee..ba1bdb197ba 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -64,16 +64,6 @@ private:
     int64_t feeDelta;
 };
 
-struct update_lock_points
-{
-    explicit update_lock_points(const LockPoints& _lp) : lp(_lp) { }
-
-    void operator() (CTxMemPoolEntry &e) { e.UpdateLockPoints(lp); }
-
-private:
-    const LockPoints& lp;
-};
-
 bool TestLockPointValidity(CChain& active_chain, const LockPoints& lp)
 {
     AssertLockHeld(cs_main);
diff --git a/src/txmempool.h b/src/txmempool.h
index f87ecc9cd08..ba1d381a5cc 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -312,6 +312,16 @@ public:
     }
 };
 
+struct update_lock_points
+{
+    explicit update_lock_points(const LockPoints& _lp) : lp(_lp) { }
+
+    void operator() (CTxMemPoolEntry &e) { e.UpdateLockPoints(lp); }
+
+private:
+    const LockPoints& lp;
+};
+
 // Multi_index tag names
 struct descendant_score {};
 struct entry_time {};

From b4adc5ad6769e4a5a6179dfff271cd4c9dc47a5b Mon Sep 17 00:00:00 2001
From: glozow <gloriajzhao@gmail.com>
Date: Fri, 3 Dec 2021 18:03:16 +0000
Subject: [PATCH 2/2] [bugfix] update lockpoints correctly during reorg

During a reorg, we re-check timelocks on all mempool entries using
CheckSequenceLocks(useExistingLockPoints=false) and remove any
now-invalid entries. CheckSequenceLocks() also mutates the LockPoints
passed in, and we update valid entries' LockPoints using
update_lock_points. Thus, update_lock_points(lp) needs to be called
right after CheckSequenceLocks(lp), otherwise we lose the data in lp.
commit bedf246 introduced a bug by separating those two loops.
---
 src/txmempool.cpp  | 5 +----
 src/validation.cpp | 2 ++
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index ba1bdb197ba..26cb2ff4b42 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -639,10 +639,7 @@ void CTxMemPool::removeForReorg(CChain& chain, std::function<bool(txiter)> check
     }
     RemoveStaged(setAllRemoves, false, MemPoolRemovalReason::REORG);
     for (indexed_transaction_set::const_iterator it = mapTx.begin(); it != mapTx.end(); it++) {
-        const LockPoints lp{it->GetLockPoints()};
-        if (!TestLockPointValidity(chain, lp)) {
-            mapTx.modify(it, update_lock_points(lp));
-        }
+        assert(TestLockPointValidity(chain, it->GetLockPoints()));
     }
 }
 
diff --git a/src/validation.cpp b/src/validation.cpp
index 203bd576765..68729e48637 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -378,6 +378,8 @@ void CChainState::MaybeUpdateMempoolForReorg(
                 }
             }
         }
+        // CheckSequenceLocks updates lp. Update the mempool entry LockPoints.
+        if (!validLP) m_mempool->mapTx.modify(it, update_lock_points(lp));
         return should_remove;
     };