From 1b0b3e2c2cbb60bb6a4e352c9bad221ec416e340 Mon Sep 17 00:00:00 2001
From: stratospher <44024636+stratospher@users.noreply.github.com>
Date: Thu, 19 Mar 2026 22:07:26 +0530
Subject: [PATCH] validation: remove redundant marking in FindMostWorkChain

since ed764ea, all descendants in m_block_index are required to be
marked BLOCK_FAILED_VALID when an invalid block is encountered,
as enforced by a CheckBlockIndex assert.

remove the now-redundant marking in FindMostWorkChain's inner loop,
so it is only responsible for cleaning up setBlockIndexCandidates,
not for modifying block validity state
---
 src/validation.cpp | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/src/validation.cpp b/src/validation.cpp
index 00c1bab501f..e0a8c1b38db 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -3142,13 +3142,10 @@ CBlockIndex* Chainstate::FindMostWorkChain()
                 CBlockIndex *pindexFailed = pindexNew;
                 // Remove the entire chain from the set.
                 while (pindexTest != pindexFailed) {
-                    if (fFailedChain) {
-                        pindexFailed->nStatus |= BLOCK_FAILED_VALID;
-                        m_blockman.m_dirty_blockindex.insert(pindexFailed);
-                    } else if (fMissingData) {
-                        // If we're missing data, then add back to m_blocks_unlinked,
-                        // so that if the block arrives in the future we can try adding
-                        // to setBlockIndexCandidates again.
+                    if (fMissingData && !fFailedChain) {
+                        // If we're missing data and not a descendant of an invalid block,
+                        // then add back to m_blocks_unlinked, so that if the block arrives in the future
+                        // we can try adding to setBlockIndexCandidates again.
                         m_blockman.m_blocks_unlinked.insert(
                             std::make_pair(pindexFailed->pprev, pindexFailed));
                     }