Bitcoin Core PR 35100 changes PSBT merge locktime selection
Bitcoin Core PR #35100, submitted Apr 27, 2026 by nervana21, changes `joinpsbts` so merged PSBTs use the maximum `nLockTime` among PSBTs with non-final sequence inputs, instead of the minimum. It also updates RPC docs and extends `rpc_psbt` test coverage.
Mechanically, this makes the merged transaction respect the strictest locktime constraint in the input set, so one party’s PSBT cannot make the aggregate transaction minable earlier than another party intended. The feed frames this as validation fidelity under existing protocol semantics, not a consensus-rule change.
Caveat: the same reasoning chain notes this can delay finality when the maximum locktime is significantly higher than the minimum, and the necessity is less clear when all inputs are `SEQUENCE_FINAL`, since those are not locktime-constrained.
Source:
#Bitcoin #BitcoinCore #PSBT #RPC #Locktime
GitHub
rpc: Merge joinpsbts locktimes correctly by nervana21 · Pull Request #35100 · bitcoin/bitcoin
joinpsbts previously took the minimum nLockTime across the PSBTs being merged, so the combined transaction could be minable earlier than the strict...
GitHub
rpc: Merge joinpsbts locktimes correctly by nervana21 · Pull Request #35100 · bitcoin/bitcoin
joinpsbts previously took the minimum nLockTime across the PSBTs being merged, so the combined transaction could be minable earlier than the strict...