Invalid block 509557

Why it is invalid

rule

already_confirmed_in_parent

Core reject

bad-txns-inputs-missingorspent

Core check

ConnectBlock via CheckTxInputs

CI checks

A complete block whose named parent_txid is a non-coinbase transaction in both that body and its canonical parent. The parent's ordered txid list must reproduce the merkle root of a hash-verified parent header, and the canonical hash at height minus one must equal prev_hash. Require parent_kind=canonical and body-derived coinbase fields with coinbase_height equal to the record height.

Incident note: 507514, 509557, 515319 and 534339 - AntPool parent-transaction reuse (2018)

Each block includes non-coinbase transactions already confirmed in the canonical parent named by its header, so their inputs were already spent and ConnectBlock fails with bad-txns-inputs-missingorspent. The dataset calls this already_confirmed_in_parent, separately from forward spends and missing unconfirmed parent transactions.