[31.x] Backport #35168 #36361

pull fametrano wants to merge 2 commits into bitcoin:31.x from fametrano:31.x-backport-35168 changing 3 files +43 −1

fametrano commented at 9:35 PM on September 27, 2026: contributor
Backports:
- #35168
v31.1 still carries the pre-fix LoadBlockIndex, which re-adds a pruned block to m_blocks_unlinked when its parent is header-only (#35050). On the next block connected, CheckBlockIndex hits Assertion failed: (!foundInUnlinked). -checkblockindex is on by default only on regtest, so this crashes functional-test suites run against 31.x, not mainnet nodes.

Both commits cherry-pick cleanly with -x. The only difference from master is the surrounding context in test_runner.py. The added feature_prune_stale_fork.py fails against the v31.1 release binary on the assertion above and passes on this branch (2/2 each, macOS arm64, built from depends).

I left the release-notes entry to whoever assembles the 31.x notes.

validation: Don't add pruned blocks to m_blocks_unlinked on startup

LoadBlockIndex() adds to m_blocks_unlinked based only on nTx > 0, without
checking BLOCK_HAVE_DATA. Pruning preserves nTx but clears BLOCK_HAVE_DATA,
so a pruned block whose parent was header-only gets re-added on every
restart, causing the CheckBlockIndex() assertion that entries must have
data on disk to fail.

Check that BLOCK_HAVE_DATA is set before inserting into m_blocks_unlinked.

Fixes #35050.

(cherry picked from commit 0e4b0bacecf94063342c7f9eb9b03dac8a7a7936)

6cedc5d47e

test: Add coverage for m_blocks_unlinked invariant in LoadBlockIndex

A pruned stale-fork block whose parent doesn't have any transactions
shouldn't be added to m_blocks_unlinked when starting up a node.

(cherry picked from commit 3f44f9aef7ccd0417fcd0c2f33f20615ea5c11e6)

5ec487b9ae

DrahtBot added the label Backport on Sep 27, 2026
DrahtBot commented at 9:35 PM on September 27, 2026: contributor



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#35050 validation: `Assertion failed: (!foundInUnlinked)`#35168 validation: Don't add pruned blocks to `m_blocks_unlinked` on startup

[31.x] Backport #35168 #36361

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